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347 Cards in this Set
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Any group 1 metal is highly reactive with water and bc water is readily available we have to be extremely precautions |
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A beaker should not be used |
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Bc heat is the difference add heat then separate |
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Cr=52g, 16x3=48 so we need 3 O |
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What if it was asking for nitrogen |
Since it's asking for O it's that amswer If NITROgen it would be 5.15 at the bottom |
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If the d orbital is filled you count it in the valence |
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The s is the first to go |
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B is the only that skips |
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The larger the number the weaker the lattice energy |
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Bh3: dipoles go in and cancel CO2: no LP and dipoles cancel going in diff directions CCL4 and AlCl3: same as CO2 NH3: has lp even tho dipoles point the same way it'd polar bc of LP |
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4= bond order for each bond ÷ 3=total numbers = 1.33 |
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-The more negative enthalpy mean it's easier for C to the an e-= higher electron affinty -carbon releases more energy too -electron negative has nothing to do with affinity -answer is D bc its better to have a half filled or fully filled shell |
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As is a metalliod with Si |
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-O is the highest which leaves answers A and B -with ionization energy if in the same row the lower A# is the stronger IE -RULE: N>O and Be>B |
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Alkali metal |
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Whichever has the same molecular weight |
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Always use the combined gas law when given a gas question that tells you the starting conditions and ending set of conditions and asks you to solve something on one side or the other |
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Games are the most compressible form B |
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Answer is B bc they are the right size and are diatomic |
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B |
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D is the correct answer |
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it s teling you that its going from a solid to a gas form bc the solid is boiling = sublimation |
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-IMF 1st then size 1. F does hbonding so its the strongest, the rest is dipole so they are the same 2. size = I>Br> Cl |
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spectators is the one that gets crossed out whih are the aq on both sides -the solids are used in the net |
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ppt is the only one that will not change the concentration -if a subs ppt it just changes itd state nothing else |
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i3 bc NaCr breaks off into 3 |
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the easier the salts the dissolve the more conductive it will be |
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What's the difference BTW endo and ender |
endothermic is a relative change in enthalpy, whilst endergonic refers to the relative change in free energy of a system. |
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D is the right answer |
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It's called the transition state |
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It's D |
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-the concentrations of react and prod do remain the same but do they do not cease, hings are srill moving from side to side the rates are equal -concent do not remain the same |
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Q Q>K=Reactants |
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label these: rate of formation, rate law, Keq/ rate constant, Ksp A+2B>>>>C+2D |
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A Ksp water |
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C |
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D |
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E |
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A |
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K>1 K<1 |
Prod React |
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^V=decrease P means whats decrease V = increase in P means what? |
- shift to side with more gas molecules -shift to side with less gas molecules |
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E |
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-only SA and SB can dissociate -monoprotic does it once and diprotic does it twice -this question wants a monoprotic SA |
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list the SA and SB |
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2 is confusing but temperature can change and still have a neutral pH |
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the higher the Ka the stronger the acid. -the question is asking for the stringest base so we want the weakest Ka |
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How tomknownifnsalts are basic or acidic |
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-it wants to know which is a base -bronsted acid has to have a source that can give off H+, a base accepts a H+ 1. split NaCN and the (-) on CN can take a H off of a H20 to make HCN and OH. So it took an H+= base 2. does the same it takes an H+ 3. RULE: if your ionic cmpd gives off an anion that is the CB of SA, then it will not increase pH. this is what 3 does cl- is a CB of HCl CORRECT ANSWER IS B |
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NaBr = both neutral KF= N and Base NH4I= A and N answer is C |
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AgCL will form a is the CB of a SA which will dissociate rapidly in water -BaF2 is not a CB oF SA so it will dissociate better in HCl -PbI2 will form a is the CB of a SA which will dissociate rapidly in water |
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ice table is better to understand |
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what if it was a WB with a SA |
-the equivalency point will be a wA so the PH would have to be in the WA pH range |
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the higher the PKa the lower the kA and the weaker the acid -so we have a weak CA = SB -weak CA/CB= SB/SA -Strong CA/CB= weak SB/SA |
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Its a SB so it dissociates twice so 2(0.1) = 0.2 |
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its a base bc CLO can take an H but its not the CB of a SA so it is a WB The answer is B |
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B |
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Neutralization and salt EX: NaNO3 salt |
A salt forms btw a SA and SB to make a water and salt |
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Answer is B |
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10 is a Wb so you need a WA and SB |
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^Ecell= stronger oxidant= stronger reducer = cathode Lower Ecell = stronger reductant = stronger oxidizer = anode - B: is wrong bc Co is a oxidant and wants to get reduced not reduce others - C: wrong bc Cu has a lower Ecell than Co -E: NJ wants to get reduced -D is right |
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-increasing Ecell means anything that will shift to the prod side and that's C |
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E IS THE RIGHT ANSWER |
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-Look at the overall equation you see that the 2nd equation has to be flipped to match which flips the sign to negative -usenthe Ecell= Ered + Eox to find the Ecell of the 2nd equation - answer is B |
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CIt is 2Cr 3+ bc there is 2 Cr on the reactant side and we have to balance CIt is 2Cr 3+ bc there is 2 Cr on the reactant side and we have to balance |
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Bc rxn isn't spont so it needs help |
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The only one that dies oil reg |
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What does Ecell tell you |
^Ecell = spont= ^red/ot= wants to be reduced= product favored |
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How do the rate law graphs look |
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Equilibrium constant will change as what changes |
Temp |
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Keq vs Ksp in terms of solubility |
Keq is a solute with any solventKsp is a solute with water The higher they are the more soluble they are in their respective solvents Keq is a solute with any solventKsp is a solute with water The higher they are the more soluble they are in their respective solvents Keq is a solute with any solventKsp is a solute with water The higher they are the more soluble they are in their respective solvents |
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Acid strength of binary acids is determined by what |
Electronegativity and size If in the same column the bigger it is the more acidic Electronegativity and size If in the same column the bigger it is the more acidic |
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Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass Which statement best explains why iodine is a solid, but bromine is a liquid at STP?A. Bromine has less London dispersion forces due to a higher molar masB. Bromine has more London dispersion forces due to a lower molar massC. Iodine has less London dispersion forces due to a higher molar massD. Iodine has more London dispersion forces due to a higher molar massE. Iodine has more London dispersion forces due to a lower molar mass |
-different MP or BP due to different intermolecular forces-A higher molar mass results in increased London dispersion forces.D. Iodine has more London dispersion forces due to a higher molar mass -different MP or BP due to different intermolecular forces-A higher molar mass results in increased London dispersion forces.D. Iodine has more London dispersion forces due to a higher molar mass -different MP or BP due to different intermolecular forces-A higher molar mass results in increased London dispersion forces.D. Iodine has more London dispersion forces due to a higher molar mass |
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what are the colligative properties |
FP, BP, VP, OP |
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Which of the following will affect the rate of an irreversible chemical reaction? A. Change in enthalpy of the reaction B. Change in entropy of the reaction C. Concentration of products D. Concentration of reactants |
-Concentration of reactants -think of what changes the rate of the rxn: collisons, temp. -if it is irreversible then it can only go forward so only reactants matter |
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A first order reaction has a half-life of 90 minutes. What is the decay constant in hour-1? A. 90 / (0.693) B. (0.693) / 1.5 C. (0.693)(1.5) D. (0.693) / 90 E. (0.693)(90) |
B. (0.693) / 1.5 -t1/2 = 0.693/k -We are given time in minutes and the final rate constant should be in hours. There are 1.5 hours in 90 minutes. Substitute in the values given: k = (0.693)/1.5 |
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Which ion is diamagnetic in the ground state?A. C2- B. N2- C. Li+ D. S2+ |
-para= unpaired and dia is paired C. Li+ |
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A one step reaction has forward and backward activation energies that are equal to each other. Which of the following must be true? A. ΔH = 0 B. Δq = 0 C. ΔS = 0 D. It must be a catalyzed reaction |
if the forward and backward Ea are the same then the reacts and prods must be at the same level so enthalpy is the same A. ΔH = 0 |
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Which of the following elements is capable of expanding its valence shell? A. Oxygen B. Phosphorus C. Carbon D. Nitrogen E. Helium |
it is talking about the octet rule and who can go past it. -elements in the third row (n=3) of the periodic table are capable of expanding their valence shell and breaking the octet rule. -the most common ei s P, S and Cl |
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Which set of quantum numbers describes the valence electron in ground state lithium? A. 2, 0, 0, +1/2 B. 2, 0, 1, +1/2 C. 2, 1, 1, +1/2 D. 3, 0, 0, -1/2 E. 3, 1, 0, +1/2 |
A. 2, 0, 0, +1/2 n=2, l=s=0, ml = 0, ms= dont matter |
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N2(g) + 3H2(g) ⇌ 2NH3(g) ; ΔH° = -92.22 kJ•mol-Which change would decrease the Keq in the above reaction? A. Increasing the temperature B. Decreasing the temperature C. Increasing the pressure D. Decreasing the pressure |
A. Increasing the temperature -only temp acan effect it and by increasing it it causing a shift to the reactants which decreases the Keq -to increase the Keq you want to shift to the prod |
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diff between bronsted and lewis |
-bron: acid will donate H and base accepts -lew: base donates electron pairs and acid acceots |
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Which of the following is the best Lewis acid?A. NH3 B. AlCl3 C. C6H6 D. CCl4 E. CH4 |
B. AlCl3 -lew: base donates electron pairs and acid acceots |
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Which of the following acts as a reducing agent and which would be the best OA? A. Cl- B. O2 C. F2 D. Zn2+ E. Cl2 |
ra=oil= Cl- is the one that can lose e- oa= reg = Zn2+ = needs to gain e- |
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What is the sum of the coefficients of the complete balanced equation from combusting C2H6O? |
The balanced equation for the combustion of ethanol (C2H6O) is 1 C2H6O + 3 O2 → 2 CO2 + 3 H2O From the balanced equation, we find 1 + 3 + 2 + 3 = 9. |
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Two samples of matter from two different sources are analyzed and have the same mass percent composition of their elements. What can the samples be classified as? A. Homogenous mixture B. Heterogenous mixture C. Same element D. Same compound E. Saturated solution |
-pure subs(1 formula): -element: Au, Ag -cmpd: C6H12O6 or H2O -mix (2+ formulas: -homo(uniform), ex NaCl w/ water. It can look homo but chemically there can be diff conc -heter: (not uniform) ex dirt(diff colors) C. Same element |
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Which of the following compounds has the highest boiling point? A. Carbon tetrafluoride (CF4) B. Carbon tetrachloride (CCl4) C. Carbon tetrabromide (CBr4) D. Carbon tetraiodide (CI4) |
-IMF then size for BP -they are all LD. CF4 is not hydro bc there it is not HF -so it goes by size and CI4 is the biggest |
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A solution of Mg(OH)2 in water becomes saturated. The addition of a strong acid to this solution will cause which of the following? Mg(OH)2(s) ⇌ Mg2+(aq) + 2OH-(aq) |
Mg(OH)2 is insoluble but some of it will dissolve. Bc it is saturated all of it than can dissolve will dissolve. - If a strong acid is added, it will combine with the OH- to form H2O. Because some of the OH- has been removed,the reaction will shift to the right to restore equilibrium. Thats when Mg2+ will increase |
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Describe the reaction below: PCl3(g) + Cl2(g)→ PCl5(g) ; ΔHf = -87.9 kJ/mol A. Spontaneous at all temperatures B. Nonspontaneous at all temperatures C. ΔGrxn < 0 only at low temperatures D. Spontaneous only at high temperatures E. ΔGrxn < 0 only at high temperatures |
C. ΔGrxn < 0 only at low temperatures |
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If 65 grams of sodium azide (NaN3, 65 g/mol) decomposes to form sodium and nitrogen gas, how many moles of nitrogen gas are formed? |
2NaN3>>> 2Na + 3N2 solves = 1.5 |
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How many grams of HCl (36 g/mol) are needed to react with Pb(OH)2 (241 g/mol) in order to produce 100g of PbCl2 (278 g/mol)? Pb(OH)2 + 2 HCl → 2 H2O + PbCl2 |
P1=20,000 n1= total # of moles at the start = 3 n2 = 2 Temp constant and it is a closed chamber which means volumes is constant 20000/3 = P2/2 so 40,000/3 |
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The chemical equilibrium given below is for a system in a closed vessel held at constant temperature. What value is needed to determine the equilibrium constant? Na2CO3(s) ⇌ CO2(g) + Na2O(s) |
bc Na2CO3 and Na2O are solids we only need CO2 |
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If the conjugate base of molecule X has a pKb of 1.4, what would you expect molecule X to be? A. Strongly acidic B. Weakly acidic C. Neutral D. Weakly basic E. Strongly basic |
low pkb=high kb so its a SCB -sCB = WA B. Weakly acidic |
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A sample of a compound contains 7 g of nitrogen and 16 g of oxygen. What is the compound's empirical formula? A. N2O2 B. N0.5O C. N2O D. NO2 |
7 g of nitrogen = 0.5 moles 16 g of oxygen = 1 mole -N0.5O there cant be decimales im empirical formula so multiply by 2 NO2 D. NO2 |
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Which of the following best describes why H2O has slightly smaller bond angles than CH4?A. Polarity in hydrogen bonds causes dipole attraction C. H2O has trigonal planar geometry D. H2O has fewer electron pairs surrounding the central atom |
both are tetra but H2O has LP B. Oxygen's lone pairs repel bonding pair electrons |
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The energy of a photon is directly proportional to which of the following?A. Charge B. Wavelength C. Speed of light D. Velocity E. Frequency |
-energy and frequency are directly proportional - energy and wavelength are inversly proportional E. Frequency |
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Which of the following solutions has the highest and which has the lowest freezing point? A. 1 m H2SO4 B. 1 m C6H12O6 C. 1 m NaCl D. 1 m AlCl3 E. 1 m KCl |
highest = B. 1 m C6H12O6 -lowest = D. 1 m AlCl3 |
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Which of the following pieces of equipment would provide the most accurate volume measurement? A. Erlenmeyer flask B. Buret C. Beaker D. Test tube E. Volumetric pipette |
accuracy : volumetric pipet> vol flask = buret > grad cylinder> beaker = erlenmeyer flask E. Volumetric pipette |
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Which of the following compounds is most capable of hydrogen bonding? A. HCl B. O3 C. CH3F D. NaCl E. CH3NH2 |
E. CH3NH2 bc N is bonded to H = hbonding |
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Which of the following accurately explains why along the same period, a non-metal has a smaller atomic radius than a metal? A. Non-metals have an expanded octet B. Non-metals have higher electronegativities C. Non-metals have higher ionization energies D. Non-metals have a higher effective nuclear charge |
D. Non-metals have a higher effective nuclear charge -causes protons to cause the electrons to pull in as you go right on a row |
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The pressure of a gas is increased from 100 mmHg to 120 mmHg. What effect will this change have on the temperature of the gas? A. The temperature will increase B. The temperature will decrease C. The temperature will remain the same D. The temperature will depend on the entropy change |
-The temperature and pressure of a container are directly related. -so as temp increases so does the pressure A |
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10 g of an unknown compound is added to water to form a 7.89 molar solution. If two liters of solution are present, what is the molar mass of the unknown compound? set up the problem dont solve |
molar mass = 10 / (7.89)(2) |
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Which of the following liquids would have the highest volatility? A. A liquid with hydrogen bonds B. A liquid with ionic bonds C. A liquid with a high viscosity D. A liquid with London dispersion forces E. A metal in liquid form |
-the weaker the IMF the more volatile bc theyre easier to disturb D. A liquid with London dispersion forces |
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After 220 million years, how much of a 100-gram sample of Uranium-235 would remain, assuming a half-life of 700 million years? |
The half-life of Uranium-235 is 700 million years. The number of half-lives that have passed is 220 / 700. If you didn't know which number to put on top, think about the amount of time that has passed. It's only 220 million years, which is less than 1 half life (700 million). It makes sense our fraction is less than one then. 100(.5)^(220/700) |
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Bismuth-209 emits an alpha particle. What is the product of this nuclear decay? A. Thallium-205 B. Lead-207 C. Bismuth-205 D. Polonium-207 E. Astatine-213 |
A. thallium |
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solubility rules |
1. Most Group 1 metal cations, NO3–, ClO4–, C2H3O2–, SA and NH4+ salts are soluble. 2. Most Ag+, Pb2+, S2-, OH–, Hg2+, CO32-, and PO43- salts are insoluble. 3. The solubles generally trump the insolubles. |
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Aqueous ammonium sulfide is added to a solution of iron (II) chloride. What are the spectator ions in this reaction? A. NH4+ and S2- B. NH4+ and Cl- C. S2- and Cl- D. S2- and Fe2+ E. Cl- and Fe2+ |
NH4+ and Cl- is soluble S and Fe is not soluble |
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The decomposition of A into B and C was monitored and the following graph was obtained with the corresponding equation for the best fit line. What is the rate constant for the decomposition of compound A? |
[]=zero order ln[]=1st 1/[]= 2nd order this is 1st order so the rate is the slope is 1st degree |
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During a titration experiment, the titrant is placed in which of the following A. Flask B. Buret C. Beaker D. Graduated cylinder E. Pipette |
buret to slowly titrate |
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An object releases heat into the surroundings but is NOT doing work. What best describes a quality of this object? A. -ΔE B. ∆U = 0 C. +ΔV D. +q E. ΔT = 0 |
∆E = q + w -q+w = -E |
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If the surroundings are doing work on the system with no heat being produced, which of the following is true? A. -w B. +ΔE C. +q D. -ΔE |
∆E = q + w w+q= E B. +ΔE |
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The solubility of BaSO4 in water is 2 mg/L at 25 oC. When 2 mg BaSO4 is added to 100 mL of water, some of the solid dissolves while 1.8 mg remains as precipitate. Which of the following describes the solution? A. Unsaturated B. Saturated C. Supesatuturated D. Dilute E. Pure |
unsaturated= low amounts of solute added to solvent supersaturated= it fully dissolves saturated= partially dissolved |
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Which of the following compounds would have Lewis dot diagrams constructed with the same number of valence electrons as NH4+? A. NO3- B. H2O C. CN- D. SO3 E. BF3 |
- valence electrons in NH4+ is: 5 + 4 – 1 = 8. -V.E. for H2O: 2(1)+6 = 8 B. H2O |
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Which of the following would be the empirical formula of a compound that has 4 moles of oxygen and 10 moles of nitrogen? A. N2O B. N2O4 C. N5O2 D. N10O4 |
-calculate the mole ration divide by the smaller # - 4/4 moles of oxygen = 1 mole oxygen - 10/4 moles of nitrogen = 2.5 mole nitrogen -if decimal is produced multiply 2(N2.5O) = N5O2 |
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What is an activated complex? |
-also known as the transition state - it is an unstable arrangement of atoms that exists momentarily at the peak of the activation energy barrier |
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Which process would be used to separate two miscible liquids? |
distillation |
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What is the maximum number of electrons that can be held in the fourth energy level? |
2+6+10+14= 32 |
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What is the mass percent of methanol in a solution prepared by diluting 16 grams of methanol with 32 grams of water? |
- mass % =(grams solute/ grams solution) x 100 - (16/16+32) = 1/3 x 100 = 33 |
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A gas cylinder has an internal volume of 165 liters. How many moles of nitrous oxide are in the tank? Assume the apparatus is at sea level and the ambient temperature is 22° C. |
think gas when you see cylinder in chem -ideal gas is the only one that can cover this |
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To separate a homogeneous mixture of salt water, which of the following pieces of laboratory equipment is necessary? A. Buret B. Pipet C. Condenser D. Filter E. Separatory funnel |
condenser |
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When the following reaction is balanced in acidic solution using whole number coefficients, what is the coefficient of H+? CrO42- → Cr2O72- |
Balance the equation to solve for the coefficient of H+: 1. Balance the chromium: 2CrO42- → Cr2O72- 2. Balance the oxygens by adding H2O: 2CrO42- → Cr2O72- + H2O 3. Balance the hydrogens by adding H+. Because this is in acidic solution, the H+ will be in the final half-reaction equation. 2H+ + 2CrO42- → Cr2O72- + H2O 4. Add electrons to balance the charges, as needed. In this case no electrons are needed. 2H+ + 2CrO42- → Cr2O72- + H2O |
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How many total electrons does Sn have in its p-subshells? A. 6 B. 12 C. 18 D. 20 E. 24 |
1s22s22p63s23p64s23d104p65s24d105p2 6+6+6+2 = 20 |
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10 mL of 1 M salt water is added to 40 mL of water. What is the relative concentration of salt in the new solution? A. 10% B. 20% C. 25% D. 40% E. 50% |
M1V1 = M2V2 (1 M) (10 mL) = M2 (50 mL) M2 = (1 M) (10mL) / (50 mL) M2 = 0.2 M x 100 = 20% |
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Calculate the work done by an ideal gas on its surroundings when the gas is heated at constant pressure of 1 atm from volume 50L to 100L at 298K. |
W=-P(v2-v1) W= -1atm(100-50) W= -50 |
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H nmr |
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Naturally occurring boron (10.8 u) exists in two isotope forms: B-10 (10.013 u) and B-11 (11.093 u). Which of the following statements is true? A. All naturally occurring B atoms have a mass of 10.8 u. B. B-11 is the most abundant isotope. C. Naturally occurring boron is almost pure B-10. D. Naturally occurring boron is a mixture of equal amounts of the two isotopes. E. Naturally occurring boron is radioactive. |
Boron has two isotopes: B-10 with a mass of 10.013 and B-11 with a mass of 11.093. Of the two isotopes, B-11 is the most abundant because the atomic weight of boron is closest to the mass of B-11. |
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An element X forms an oxide X2O3 with a mass ratio of 0.50 g X / 1 g O. What is the atomic mass of X? A. 12.0 amu B. 16.0 amu C. 24.0 amu D. 32.0 amu |
You can also solve this problem using logic to avoid calculations:From the question stem we know the mass of X is half (0.5 g : 1 g) the mass of O. The mass of O3 is 48 amu, this means that the mass of X2 is 24 amu.Therefore, the mass of X is 12 amu. |
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Which of the following 0.25 M solutions would exhibit the lowest electrical conductivity? A. HCl B. K2SO4 C. NaCl D. HF E. Ba(NO3)2 |
-electrical conductivity increase with the more ions a ionic (nm +m) molecule has -if there is a tie, it comes down to solubility in water. the more soluble the higher the electroconductivity will be. - A,C,D all have the same amount but HF is the least soluble based on solubility rules and HCl is a SA |
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For the reaction 2NO(g) + O2(g) → 2NO2(g), the concentration of NO was monitored from 0 to 100 seconds. Given the following data, what is the average rate of disappearance of NO from 0 to 100 seconds? A. 5.0 × 10–4 M/s B. 2.5 × 10–6 M/s C. 1.0 × 10–5 M/s D. 5.0 × 10–6 M/s E. 2.5 × 10–3 M/s |
you only use the coefficients like usual if you are comparing relative rates. For example, NO disappears twice as quickly as O2 because two NO react for every one O2. |
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What is the concentration of Pb2+ at equilibrium if the Ksp of PbCl2 equals 1.8 x 10-5 in an aqueous solution of pure water? |
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gibbs spont table |
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Which of the following reactions will be spontaneous at all temperatures? A. 2H2(g) + O2(g) → 2H2O(g) ΔH = –483.6 kJ B. 2NCl3(g) → N2(g) + 3Cl2(g) ΔH = –460.1 kJ C. N2(g) + O2(g) → 2NO(g) ΔH = + 180.5 KJ D. 2Na(s) + Cl2(g) → 2NaCl(s) ΔH = –821.8 kJ E. C(s) + 2S(s) → CS2(g) ΔH = + 92.0 KJ |
1. in order for the rxn to be spont at all temps enthalpy needs to be negative so C and E are out 2. the entropy needs to be positive Estimate the ΔS using the number of moles of gaseous species: 2NCl3(g) → N2(g) + 3Cl2(g) ΔH = –460.1 kJ Δngas = 4 – 2 = 2, thus ΔS > 0 and the reaction is spontaneous at all temperatures. |
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What will be the effect on the solubility of BaF2 if the following changes are made: increasing temperature; adding NaF; adding HCl?A. B. C. D. E. |
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What type of nuclear reaction is involved when C-11 decays to B-11? A. Alpha emission B. Positron emission C. Beta emission D. Neutron swap E. Gamma emission |
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Calculate the heat of enthalpy, ΔHo for the following reaction, based on the bond energies provided: CH4(g) + 4Cl2(g) → 4HCl(g) + CCl4(g) Bond energies: C–H = 413 kJ / mol Cl–Cl = 243 kJ / mol H–Cl = 432 kJ / mol C–Cl = 330 kJ /mol A. [1(413) + 4(243)] + [4(432) + 1(330)] B. (413 + 243) - (432 + 330) C. [4(413) + 4(243)] - [4(432) + 4(330)] D. [1(413) + 4(243)] - [4(432) + 1(330)] E. [4(432) + 4(330)] - [4(413) + 4(243)] |
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what is avogadros number |
6.02E23/ mol |
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Which of the following processes involves the greatest increase in both enthalpy and entropy? A. Deposition B. Vaporization C. Condensation D. Melting E. Sublimation |
E. Sublimation |
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Liquid mercury in a glass buret forms a convex meniscus. All of the following are correct steps for measuring the volume of liquid mercury in a buret EXCEPT for one. Which is the EXCEPTION? A. Place the buret as straight as possible B. Position oneself eye-level to the meniscus C. Focus on the center of the meniscus D. Take a reading from the bottom of the meniscus E. Report the volume based on the buret’s smallest line markings(24%) |
polar substances are concave, np like Hg is convex -if concave take reading from bottom if convex take reading from top D. Take a reading from the bottom of the meniscus |
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What amount of heat is required to change the temperature of 1 g H2O from -10 ºC to 10 ºC if the specific heat capacity of ice is 2.1 J/g·°C, the heat of fusion of H2O is 334 J/g, and the specific heat capacity of water is 4.2 J/g·°C? |
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For which of the following reactions will the yield of products increase if NaCl is added? A. AgCl (s) + NaI (aq) ⇌ NaCl (aq) + AgI (s) B. Co2+ (aq) + 4Cl- (aq) ⇌ CoCl42- (aq) C. Mn (s) + 2HCl (aq) ⇌ MnCl2 (aq) + H2 (g) D. AgCl (s) ⇌ Ag+ (aq) + Cl- (aq) E. Na2SO3 (s) + HCl (g) ⇌ NaCl (aq) + H2SO4 (l) |
B. Co2+ (aq) + 4Cl- (aq) ⇌ CoCl42- (aq) its the only one with Cl- on the left side which will cause an increase of prod |
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A sealed system containing a liquid has its temperature lowered. Which of the following would be observed? A. The pressure of the gas would increase B. The number of particles in the gas phase would decrease C. The vapor pressure of the liquid would increase D. The boiling point of the liquid would increase |
if temp is decreased then it would go from gas to lig B. The number of particles in the gas phase would decrease |
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A sample of an ideal gas at 25oC and 1 atm has a volume of 1.2 L. What will be the volume of the same sample of gas at 0.5 atm pressure and 25oC? A. 0.60 L B. 1.2 L C. 2.4 L D. 4.8 L E. 9.6 L |
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The vapor pressure of pure liquid solvent X is 0.50 atm. When a nonvolatile substance B is added to solvent X, the vapor pressure of the resulting mixture is 0.40 atm. What is the mole fraction of B in the mixture? A. 0.20 B. 0.40 C. 0.50 D. 0.80 E. 1.0 |
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What is the concentration in molarity of a 10% (w/w) solution of HClO4 (MM = 100.46 g/mol) that has a density of 1500 g/L? A. 1.50 M( B. 3.75 M C. 25.0 M D. 40.0 M E. 66.6 M |
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An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M An aqueous solution of 0.75 M glucose has an osmotic pressure of 18.5 atm at 300 K. If the osmotic pressure is doubled, and the temperature were tripled, what would be the molarity of the resulting solution?A. 0.50 MB. 1.5 MC. 4.5 MD. 7.5 ME. 15 M |
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Which 0.1 M cation solution, when added to a 100 mL 0.1M Na2CO3 dropwise, would form a precipitate first? A. Mg2+ (Ksp MgCO3 = 1.0 × 10–5) B. Ca2+ (Ksp CaCO3 = 5.2 × 10–12) C. Hg22+ (Ksp Hg2CO3 = 9.0 × 10–17) D. Ba2+ (Ksp BaCO3 = 2.0 × 10–9) E. Fe2+ (Ksp FeCO3 = 3.5 x 10-11) |
The smaller the ksp value the faster it will ppt |
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At what temperature will the following reaction becomes spontaneous (assuming enthalpy and entropy do not change with temperature)?N2 (g) + O2 (g) → 2NO (g) ΔHo = +100 kJ/mol, ΔS = +25 J/mol K A. The reaction is spontaneous at all temperatures. B. The reaction will be spontaneous above 4000 K. C. The reaction will be spontaneous above 4 K. D. The reaction is nonspontaneous at all temperatures. E. The reaction will be spontaneous above 400 K. |
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Which of the following is correct about the two acid/base reactions shown below: A. In both reactions, water is acting as an acid B. In both reactions, water is acting as a base. C. Water does not act as either a base or an acid in these reactions. D. Water acts as an acid in reaction 1, and a base in reaction 2. E. Water acts as an acid in reaction 2, and a base in reaction 1. |
in the second one NaH and H2O act as acidsby giving away an H+ |
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Which statement explains why HI is a stronger acid than HBr? A. Iodine is smaller than bromine B. Acid strength increases as electronegativity of the halogen increases C. Iodine has a greater number of available electrons for binding D. The bond strength between H-I is lower than that of H-Br E. Acid dissociation decreases as the shielding effect increases |
bonds break easier the more acidci the molecule is = bond strength is weak |
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Which of the following is the standard reduction potential for bromine? A. Br2(l) + 2e− ⇌ 2Br−(aq) B. Br2(g) + 2e− ⇌ 2Br−(g) C. Br(l) + 1e- ⇌ Br-(l) D. Br(g) + 1e- ⇌ Br(g) E. 2Br−(l) ⇌ Br2(g) + 2e− |
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Which of the following types of molecules is characterized by low boiling and melting points? A. Ionic compounds B. Covalent compounds C. Network covalent compound D. Transition compounds E. Metallic compounds |
strength of intra: metalic> ionic> network of covalent> covalent |
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Which one of the following is the complete net ionic equation for the reaction of silver nitrate and sodium chloride? A. AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) B. Ag+(s) + NO3-(s) + Na+(s) + Cl-(aq) → AgCl(s) + Na+(aq) + NO3-(aq) C. Ag+(aq) + Cl-(aq) → AgCl(s) D. Na+(aq) + NO3-(aq) → NaNO3(aq) E. Ag+(aq) + NO3-(aq) → AgNO3(aq) |
C. Ag+(aq) + Cl-(aq) → AgCl(s) |
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Which one of the following compounds conducts electricity in an aqueous solution? A. MgCl2(s) B. C12H22O11(s) C. O2 D. PBr3(l) E. CO2(g) |
ionic conducts electricity so it would be A |
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What is the final pressure of a 100 L gas that is initially at 2 kPa and -23°C, but is then heated to 227°C at a constant volume? |
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All of the following are properties of gases EXCEPT one. Which one is the EXCEPTION? A. They are easy to compress. B. They occupy more volume than the liquids or solids from which they form C. They expand to fill their containers. D. They are effective conductors of heat. E. They exert a force on the interior surface of their container. |
D. They are effective conductors of heat. |
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he most abundant element in the universe and the earth's crust, respectively, are A. carbon and oxygen. B. hydrogen and nitrogen. C. carbon and nitrogen D. hydrogen and oxygen. E. nitrogen and helium. |
D. hydrogen and oxygen. |
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Which of the following is a strong electrolyte? A. H2O B. HF C. NaOH D. CH3OH E. C4H8O4 |
-strong electrolyte is any solute that ionizes completely (dissociates) in solution. -strong acids, strong bases, and soluble ionic salts are strong electrolytes. |
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How many lone pairs are around the central atom in xenon difluoride? A. 0 B. 1 C. 2 D. 3 E. 4 |
3 |
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Calculate the molarity of a 20.0 mL sample of HCl given that 40 mL of 0.05 M Ba(OH)2 was added to reach the equivalence point. |
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Which route of decay would result in an increased proton to neutron ratio in the emitted particle? A. Alpha decay B. Beta emission C. Positron emission D. Electron capture E. Gamma decay |
B. Beta emission |
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When the following half-reaction is balanced in basic medium, how many moles of OH- are consumed per mol of CN-? CN- → CNO- A. 1 B. 2 C. 3 D. 4 E. 5 |
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All of the following statements about compounds and mixtures are correct EXCEPT one. Which one is the EXCEPTION? A. A mixture can be separated by physical means. B. The composition of a compound is fixed. C. The composition of a mixture is variable D. A mixture’s properties are related to those of its components E. A compound can be separated by physical means. |
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50 g of hydrogen reacts with 280 g of nitrogen to form ammonia. What is the theoretical yield of ammonia produced? |
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What is the pH of a solution that has a hydroxide ion concentration of 4.98 x 10-5 M? |
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What is the specific heat capacity of a piece of copper with a mass of 20.0 g that was heated to 24.58°C and then placed in a calorimeter that contained 50 g of water at 18.4°C? The final temperature of the water and copper was 20.4°C and the specific heat of water is 4.18 J/°C•g. |
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What mass of CCl4 (in grams) is needed to dissolve 16 g of Br2 to make a 0.5 m solution of Br2? |
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what are there states at room temp metal and metaloids Hg and Br2 noble gases I2 |
s l g s |
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what exists as 2 atoms1 |
halogens, H, N,O, Br2 and I2 |
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Which of the following pieces of lab equipment is best suited for the measurement of a volume of liquid? A. Beaker B. Erlenmeyer flask C. Graduated cylinder D. Test tubeE. Buret |
C |
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What are the final products after completing and balancing the following reaction?Zn(s) + Fe2(SO4)3(aq) A. Zn(SO4)(aq) + 2 Fe(s) B. 3 Zn(SO4)3(aq) + 2 Fe(s) C. Zn2(SO4)3(aq) + 2 Fe(s) D. ZnFe(s) + 3 SO4-(aq) E. 3 Zn(SO4)(aq) + 2 Fe(s) |
E. 3 Zn(SO4)(aq) + 2 Fe(s) |
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Parallax error may occur when A. an experiment does not account for changes in altitude B. a measurement is not properly converted between the metric and customary systems. C. a meniscus in a buret is not observed directly straight on. D. an object under water is observed at an angle from above the surface. E. the concentration of an acid to be used in a titration is not first checked against a standard |
Parallax error may occur when a pointer on a meter or the surface of a liquid in a buret or pipette is not observed from straight on. |
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Which amount and concentration of base would neutralize 100 mL of 0.1 M sulfuric acid? A. 50 mL of 0.1 M Mg(OH)2 B. 50 mL of 0.3 M Mg(OH)2 C. 100 mL of 0.2 M Mg(OH)2 D. 100 mL of 0.2 M NaOH E. 100 mL of 0.3 M NaOH |
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estimate the log(7E8) |
log(1E8)=8 log(3.16E8)=8.5 log(7E8)= 8.5-9 bc 7 is bigger than 3.16 but x is not bigger than 9 log(1E9)=9 smaller number is first |
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estimate the log(7E-6) |
log(1E-6)=-6 log(3.16E-6)= -5.5 log(7E-6) = -5.5 to -5 log(1E-5)=-5 the 7 is bigger than 3.16 but smaller than 1E-5 |
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Secondary amine |
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A |
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