Chemistry - Ch 5, 7, 9

Front 1

Molecular Formula

Back 1

actal number of atoms; ex: H20

Front 2

empirical formula

Back 2

gives simplist ratios of all atoms in molecule; ex: HO

Front 3

Formula weight - Covalent and Ionic

Back 3

atomic weight times number of atoms

Front 4

1 Mole of any element equals

Back 4

same numer of molecules

Front 5

mass for one mole equals

Back 5

molar mass - mass in grams of 1 grams of any substance - g/mol

Front 6

1 mole equals

Back 6

6.022 X10 23 (avogard's ) atoms or molecules - also equals molar mass

Front 7

1 mol weight in grams

Back 7

Depends on element; total molar mass

Metal mol always in atoms; Gasses in molecules

Front 8

1 mol =

Back 8

6.022 x 10 23 atoms/molecules = molar mass in grams

Front 9

calculate mol in 2 ways

Back 9

1 mol = 6.022 x 10 23 atoms/molecules

1 mol - molar mass in grams

Front 10

to convert grams to molecules

Back 10

divide by the molar mass

Front 11

To convert mol to grams

Back 11

multiply by molar mass

Front 12

To find oxygen atoms in 500 mg of aspirin, c 9 H 8 O 4

Back 12

-change mg to grams: .500 g c9h8o4
-chamge g to mol: 1 mol = ? grams - 180.17
-change mols to atoms/molcules: 1 mol 6.022 x 20 34 molecles

Front 13

Properties of Acids

Back 13

Taste sour
corrosive
Litmus paper turns red
start with H+ except H2O
ex: H+ + H2)O+ (hydronium ion)
breakdown called ionization/dissociation

Front 14

Properties of bases

Back 14

tasteless
slippery
cleaner
corrosive
litmust paper turns blue
releases OH-

Front 15

bases are:

Back 15

compounds that accept protons (H+) (proton acceptor)

Front 16

acids are:

Back 16

compounds that donate H ion (proton) to other compounds; (proton donors)

Front 17

Bases can only be

Back 17

- or neutral

Front 18

Self-ionization of H2O

Back 18

H20 + H20 --> H30+ + OH-

Front 19

Neutral solution

Back 19

1.0 x 10 -7 M

Front 20

pH scale

Back 20

1 to 14;
1 unit of change in pH = 10 x more/less acidic

Front 21

Higher pH - acid

Back 21

less acidic

Front 22

Lower pH - acid

Back 22

stronger acid

Front 23

Higher pH - base

Back 23

more acidic

Front 24

Lower pH - base

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less acidic

Front 25

Neutral pH

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pH 7

Front 26

pH scale

Back 26

0-------------7------------14
<--acidic neutral base--->
strength strength

Front 27

Buffer -

Back 27

weak acid + conjugate base OR
weak base + conjugate acid

Front 28

Formula weight (FW)

Back 28

sum of the atomic weights in atomic mass units (amu) of all the atoms in the compounds formula; used for both ionic and molecular compounds

Front 29

Molecular weight (MW)

Back 29

used for covalent compounds only; used for covalent compounds only

Front 30

Mole

Back 30

he amount of substance that contains as many atoms, molecules, or ions as there are atoms in eaxtly 12 g of cqrbon-12; always contains the same number of formula units; scale factor for atoms and molecules

Front 31

Avogadro's number

Back 31

the number of formula units in a mole; a value that must be determined experimentally; value 6.02214199 X 10 23 formula units per mole

Front 32

molar mass

Back 32

the mass of one mole of any substance; formula weight of the substance expressed in grams;

Front 33

Find moles

Back 33

Molar mass of compound in ratio to amount of entire compound; ex:
36.0g H2) x (1 mol H20 divided by molar mass of 18 g H20) = 2.0 mol H20

Front 34

Convert moles to grams; calculate the number of grams in a beaker

Back 34

Use the molar mass of the compound X(grams divided by mol) = grams of the compound

Front 35

chemical equation

Back 35

chemical forumlas for the reactants and products with an arrow to show direction of the reaction proceeds;

Front 36

states of reactant

Back 36

(g) gas; (l) liquid; (s) solid; aq (aqueous - dissolved in H20)

Front 37

Balacing the equation

Back 37

all atoms present at the start of the reaction are still present at the end of the reaction

Front 38

acid

Back 38

substance that produces H3O+ ions in aqueous solution; proton donor

Front 39

base

Back 39

substance that produces OH+ ions in aqueous solution; proton acceptor

Front 40

hydronium ion

Back 40

an H+ ion in water immediately combines with an H20 molecule produces this; H3O+

Front 41

strong acid

Back 41

one that reacts completely or almost completely with water to form H3O+ ions

Front 42

weak acids

Back 42

smaller concentration of H3O+ ions

Front 43

strong acids

Back 43

HCl HBr HI HNO3 H2SO4 HCIO4

Front 44

strong bases

Back 44

LiOH NaOH KOH Ba(OH)2

Front 45

acid-base reaction

Back 45

proton transfer reaction

Front 46

a solution is acidic if its pH is less than

Back 46

7

Front 47

a solution is basic if its pH is greater than

Back 47

7

Front 48

a solution is neutral if its pH is equal to

Back 48

7

Front 49

buffer

Back 49

a solution whose pH chanes very little when small amounts of H3O+ or OH- ions are added to it