Chem Mod 2

Front 1

Which of the following would be immiscible (NOT soluble) with water?

Back 1

S=C=S

Front 2

Which intermolecular force or bond is primarily responsible for the solubility of H2S in water?

Back 2

dipole-dipole force

Front 3

Which action(s) will decrease the equilibrium concentration of an inert gas (such as N2) in water?1. decreasing the temperature of the water2. increasing the volume of water3. decreasing the pressure of the gas above the liquid

Back 3

3 only

Front 4

The solubility of calcium chloride is 74.5 g per 100.0 g of water at 20°C. The amount of water needed to dissolve 271 g of calcium chloride at 20°C is

Back 4

364 g

Front 5

If 2.891 g MgCl2 is dissolved in enough water to make 500.0 mL of solution, what is the molarity of the magnesium chloride solution? The molecular mass of magnesium chloride is 95.3 g/mol and the density of the solution is 1.22 g/mL.

Back 5

6.073 x 10-2 M

Front 6

What is the approximate Na+ ion concentration in a 0.75 M Na2CO3 solution?

Back 6

1.5 M

Front 7

The weight percent of concentrated HClO4(aq), molar mass = 100.5 g/mol, is 70.5% and its density is 1.67 g/mL. What is the molarity of concentrated HClO4?

Back 7

11.7 M

Front 8

What mass of calcium chloride (FW = 111.1 g/mol) is needed to prepare 2.850 L of a 1.56 M solution?

Back 8

493 g

Front 9

If 27.9 g LiCl is dissolved in 175 g H2O, what is the mass percent of LiCl in the solution?

Back 9

13.8%

Front 10

If the molality of a NaBr(aq) solution is 2.50 m, what is the weight percent of NaBr? The molar mass of NaBr is 102.9 g/mol.

Back 10

20.5%

Front 11

If 26.5 g of methanol (CH3OH); molar mass = 32.0 g/mol is added to 735 g of water, what is the molality of the methanol?

Back 11

1.13 m

Front 12

Calculate the molality of a 20.0% by mass ammonium sulfate solution. The density of the solution is 1.117 g/mL and the FW of (NH4)2SO4 is 130.1 g/mol.

Back 12

1.93 m

Front 13

What is the molar concentration of NaOH if 20.0 mL of a 10.0 M NaOH solution is mixed with 190.0 mL of water?

Back 13

1.0 M

Front 14

If 5.00 mL of 0.314 M KOH is diluted to exactly 125 mL with water, what is the mass percent concentration of the resulting solution?

Back 14

Can’t determine the concentration because you need the density of the solution

Front 15

Which response lists all the following pairs that are miscible liquids? Pair # 1. octane (C8H18) and water Pair # 2. acetic acid (CH3COOH) and water Pair # 3. octane (C8H18) and carbon tetrachloride (CCl4)

Back 15

2, 3

Front 16

The solubility of CO2 gas in water ________ with ________ gas pressure.

Back 16

increases; increasing

Front 17

Seawater contains 15 mg of gold per liter of seawater. How many liters of seawater would need to be processed to remove 1.00 g of gold?

Back 17

67 L

Front 18

What is the chloride ion concentration in a 1.7 M calcium chloride solution?

Back 18

3.4 M

Front 19

How many liters of 0.1107 M KCl contain 15.00 g of KCl (FW = 74.6 g/mol)?

Back 19

1.816 L

Front 20

If the molality of a NaBr(aq) solution is 2.50 m, what is the weight percent of NaBr? The molar mass of NaBr is 102.9 g/mol.

Back 20

20.5%

Front 21

In how many grams of water should 25.31 g of potassium nitrate (KNO3; FW=101.1 g/mol) ) be dissolved to prepare a 0.1982 m solution?

Back 21

1,263 g

Front 22

Calculate the molality of a 15.0% by mass solution of MgCl2; FW=95.3 g/mol in H2O. The density of this solution is 1.127 g/mL.

Back 22

1.86 m

Front 23

How much water would be needed to prepare 500.0 mL of a 0.100 M NaOH solution from a 2.0 M NaOH solution?

Back 23

475.0 mL

Front 24

Suppose that you have a 60.0% solution of NaOH. How many milliliters of water must be added to 30.0 mL of this solution to prepare a 35.0% solution of NaOH?

Back 24

21.4 mL

Front 25

Assuming ideal behavior, which of the following aqueous solutions should have the highest boiling point?

Back 25

0.75 m K2SO4

Front 26

Calculate the freezing point of a solution made from 22.0 g of octane (C8H18); molar mass = 114.0 g/mol; dissolved in 148.0 g of benzene. Benzene freezes at 5.50°C and its Kf value is 5.12°C/m.

Back 26

-1.16°C

Front 27

What is the molar mass of toluene if 0.85 g of toluene depresses the freezing point of 1.00 x 102 g of benzene by 0.47°C? Kf of benzene is 5.12°C/m.

Back 27

92.6 g/mol

Front 28

An organic acid was analyzed and the following percent composition was obtained: 68.85% carbon, 4.9% hydrogen, and 26.2% oxygen. A solution of 1.02 g of this compound dissolved in 10.0 g of benzene freezes at 3.37 °C. The normal freezing point of benzene is 5.50 °C and it has a Kf of 5.12 °C/m. Determine the molecular formula for this compound.

Back 28

C14H12O4

Front 29

Which of the following statements concerning osmosis is/are CORRECT?1. Osmosis involves the movement of ions through a semipermeable membrane until the charges on both sides of the membrane are equal.2. Solvents move from regions of low solute concentration to regions of higher solute concentration.3. Osmotic pressure is a colligative property.

Back 29

1, 2, and 3

Front 30

Determine the osmotic pressure of a solution that contains 0.025 g of a hydrocarbon solute (molar mass = 340 g/mol) dissolved in benzene to make a 3.50 x 102 mL solution at a temperature of 20.0 oC. (π = MRT; R=0.082 L atm/mol K)

Back 30

5.1 x 10-3 atm

Front 31

Which intermolecular force or bond is primarily responsible for the solubility of CH3OH in water?

Back 31

Hydrogen bonding

Front 32

According to Raoult's law, which statement is FALSE?

Back 32

The vapor pressure of a solvent over a solution decreases as its mole fraction increases.

Front 33

A solution is prepared by dissolving 2.0 g NaOH (FW = 40.0 g/mol) to 255 mL of solution. If the density of the solution is 1.15 g/mL, what is the mass percent NaOH in the solution?

Back 33

0.68%

Front 34

If 5.00 mL of 0.314 M KOH is diluted to exactly 125 mL with water, what is the molar concentration of the resulting solution?

Back 34

1.26 x 10-2 M

Front 35

What is the weight percent of acetic acid in 7.23 m CH3CO2H(aq)? The molar mass of acetic acid is 60.0 g/mol.

Back 35

30.3%

Front 36

What is the boiling point of a solution containing 2.33 g of caffeine, C8H10N4O2, dissolved in 15.0 g of benzene? The boiling point of pure benzene is 80.1°C and the boiling point elevation constant = 2.53°C/m. MW of caffeine = 194.19 g/mol

Back 36

82.1 C

Front 37

what is the weight percent of acetic acid in 7.23 m CH3CO2H(aq)? The molar mass of acetic acid is 60.0 g/mol?

Back 37

30.25 %

Front 38

During osmosis

Back 38

pure solvent diffuses through a membrane but solutes do not

Front 39

When 24.0 g of a simple sugar (a nonelectrolyte) are dissolved in 5.00 x 102 g of water, the solution has a freezing point of -0.47°C. What is the molar mass of the sugar? Kf of water is 1.86°C/m.

Back 39

192 g/mol

Front 40

Arrange the following aqueous solutions in order of increasing boiling points.0.050 m Mg(NO3)2; 0.100 m ethanol; 0.090 m NaCl

Back 40

Ethanol < Mg(NO3)2 < NaCl

Front 41

What is the percent CsCl by mass in a 0.711 M CsCl solution that has a density of 1.091 g/mL?

Back 41

11.0 %

Front 42

If 4.49 g NaNO3 (FW = 85.0 g/mol) is dissolved in enough water to make 250.0 mL of solution, what is the molarity of the sodium nitrate solution?

Back 42

2.11 x 10–1 M

Front 43

A solution of HCl is prepared by dissolving 5.00 mL of HCl (d = 1.23 g/mL) in 55.0 g of water. What is the mass percent HCl?

Back 43

10.0 %

Front 44

A solution of ethylene glycol in water such as in an antifreeze solution has a boiling point

Back 44

> 100°C and a freezing point < 0°C.

Front 45

An oxide of phosphorus contains 56.4% oxygen. A solution of 1.18 g of this compound dissolved in 10.0 g of benzene freezes at 3.37 °C. The normal freezing point of benzene is 5.50 °C and it has a Kf of 5.12 °C/m. What is the molecular formula for this compound?

Back 45

P4O10

Front 46

A 20.0 mL sample of 0.1015 M nitric acid is mixed with 230.0 mL of water. What is the molar concentration of nitric acid in the final solution?

Back 46

8.12 x 10-3 M

Front 47

Calculate the molality of a solution containing 14.3 g of NaCl (FW = 58.5 g/mol) in 42.2 g of water.

Back 47

5.80 m

Front 48

Find the mass percent of CuSO4 (molar mass = 159.5 g/mol) in a 1.22 molar solution with a density of 1.30 g/mL.

Back 48

15.0%

Front 49

An ethanol solution is prepared by dissolving 15 mL of ethanol in 25.0 mL of water. If the density of ethanol is 0.79 g/mL and the density of water is 1.0 g/mL, what is the mass percent of ethanol in the solution?

Back 49

32 %

Front 50

The weight percent of concentrated H2SO4, molar mass = 98.0 g/mol, is 96.0% and its density is 1.84 g/mL. What is the molarity of concentrated H2SO4?

Back 50

18.0 M

Front 51

Which intermolecular force or bond is primarily responsible for the solubility of NaCl in water?

Back 51

Hydrogen bonding

Front 52

Which of the following liquids will be miscible with water in any proportions: ethanol (CH3CH2OH), carbon tetrachloride (CCl4), hexane (C6H14), and/or formic acid (HCO2H)?

Back 52

Ethanol and formic acid

Front 53

The osmotic pressure of blood is 7.65 atm at 37 °C. What mass of glucose C6H12O6, molar mass = 180.2 g/mol is needed to prepare 5.00 L of solution for intravenous injection? The osmotic pressure of the glucose solution must equal the osmotic pressure of blood.(π = MRT; R=0.082 L atm/mol K)

Back 53

271 g

Front 54

A hydrocarbon was analyzed and the following percent composition was obtained: 82.76% carbon and 17.24% hydrogen. A solution of 60.3 mg of this compound dissolved in 2.5 g of benzene freezes at 3.37 °C. The normal freezing point of benzene is 5.50 °C and it has a Kf of 5.12 °C/m. What is the molecular formula for this compound?

Back 54

C4H10

Front 55

Concentrated sodium hydroxide is 19.4 M and has a density of 1.54 g/mL and a molar mass of 40.0 g/mol. What is the molality of concentrated NaOH?

Back 55

25.4 m

Front 56

Calculate the percent by mass of potassium nitrate in a solution made from 45.0 g KNO3 and 295 mL of water.

Back 56

13.3 %

Front 57

Calcium carbonate, or limestone, is relatively insoluble in water. At 25°C, only 5.8 mg will dissolve in 1.0 liter of water. What volume of water is needed to dissolve 5.0 g of calcium carbonate?

Back 57

8.6 x 102 L

Front 58

Which intermolecular force or bond is primarily responsible for the solubility of Cl2 in CCl4?

Back 58

Dispersion forces

Front 59

Calculate the molality of a solution that contains 5.0 g of HCl (FW = 36.5 g/mol) in 2.00 x 102 mL of water.

Back 59

0.18 m

Front 60

If 26.5 g of methanol (CH3OH); molar mass = 32.0 g/mol is added to 735 g of water, what is the molality of the methanol?

Back 60

1.13 m

Front 61

What is the boiling point of a solution containing 2.33 g of caffeine, C8H10N4O2; MW=194.0 g/mol; dissolved in 15.0 g of benzene? The boiling point of pure benzene is 80.1 °C and the boiling point elevation constant, Kb is 2.53 °C/m.

Back 61

82.1 °C

Front 62

Determine the osmotic pressure of a solution that contains 0.025 g of a hydrocarbon solute (molar mass = 340 g/mol) dissolved in benzene to make a 3.50 x 102 mL solution at a temperature of 20.0 oC. (π = MRT; R=0.082 L atm/mol K)

Back 62

5.1 x 10-3 atm

Front 63

Calculate the molality of a 20.0% by mass ammonium sulfate solution. The density of the solution is 1.117 g/mL and the FW of (NH4)2SO4 is 130.1 g/mol.

Back 63

1.93 m

Front 64

How many grams of water are needed to dissolve 27.8 g of ammonium nitrate NH4NO3 (FW = 80.0 g/mol) in order to prepare a 0.452 m solution?

Back 64

769 g