STUDY GUIDE

Question 1

Convert between pressure units.

Answer 1

Pa = 1n/m^2
1atm = 101325 Pa
1atm = 760 mmHg
1torr = 1mmHg

Question 2

Understand the gas laws to determine the pressure-volume, volume-temperature, pressure-
temperature and volume-moles relationships, and perform calculations to determine these
variables under a specified set of conditions.

Answer 2

Boyle’s law: the volume of a gas at constant temp and moles is inversely proportional to the pressure
P1V1 = P2V2

Charles’s law: the volume of a gas, at constant pressure and moles is directly proportional to its absolute temperature(in kelvin)
V1/T1 = V2/T2

Avogadro’s law: the volume of a gas at constant temp and pressure is directly proportional to the number of moles of gas
V1/n1 = V2/n2

Combined gas law: P1V1/T1 = P2V2/T2

Ideal gas law:a hypothetical gas whos P,V,T relationships are described completely by the ideal gas equation/ law (R=0.0821Latm/molK)
PV = nRT

Gay-lussac’s law: The pressure of a gas is proportional to temperature at constant volume and moles of gas
P1/T1 = P2/T2

Question 3

Use the combined gas law to determine the P, V, or T under a specified set of conditions

Answer 3

P1V1/T1 = P2V2/T2

Question 4

Use the ideal gas law to determine P, V, T, or n.

Answer 4

PV = nRT

Question 5

Use the ideal gas law to determine the volume or moles of gaseous products or reactants in
chemical reactions involving gases

Answer 5

n = PV/RT
V= (nRT)/P

Question 6

Relate total pressure and partial pressure, including determining the partial pressure of a gas in
a gas mixture, and determining the pressure of a gas collected over water.

Answer 6

Partial pressure: the pressure due to any individual component in a gas mixture (fractional composition x total pressure)

Dalton’s law of partial pressures: the sum of the partial pressures of each component in a gas mixture must equal the total pressure

Ptotal= P1+P2+P3+P4+…

Question 7

Perform stoichiometric calculations for gases in chemical reactions

Answer 7

Vgas —PV=nRT—> moles of gas—->moles of other reactant or product

Question 8

Calculate mass percent and use mass percent in calculations as a conversion factor.

Answer 8

( Mass solute/ Mass solution ) x 100

Question 9

Calculate molarity and use molarity in calculations as a conversion factor.

Answer 9

M (molarity) = moles solute/Liter solution

Question 10

Solve solution dilution problems.

Answer 10

M1V1 = M2V2

Question 11

Solve solution stoichiometry problems, including calculating the volume of a reactant of
known concentration required to react with a known volume and molarity of a second reactant.

Answer 11

Volume solution A<—molarity A—> MolA<——>MolB<—-molarity B—->Volume solution B

Volume gas A<—PV=nRT—>Mol A<——>Mol B<—PV=nRT—-> Volume gas B

Question 12

Calculate molality.

Answer 12

m = Moles of solute / kg solvent

Question 13

Calculate the freezing point and boiling point of a given solution.

Answer 13

-DTf(change in temp of freezing point)

-m(molality of the solution)

-Kf(freezing point depression constant for a solvent) (1.86C kg solvent/mol solute = Kf (h2o)

-DTb(change in temp of boiling point)

-Kb(Boiling point elevation constant for a solvent) (0.512C kg solvent/mol solute = Kb (h2o)

-Freezing point depression calculation:DTf=m x Kf
0 C - DTf = answer

-Boiling point evaluation calculation: DTb= m x Kb
100 C - DTb = answer

Question 14

Identify common acids and bases and describe their key characteristics.

Answer 14

Acids: citric acid, HCl, HC2H3O2, H2CO3
Characteristics-> sour taste, react with metals, turn blue litmus paper red

Bases: NaOH, KOH, NaHCO3, NH3
Characteristics-> bitter taste, slippery feel, turns red litmus paper blue

Question 15

dentify Arrhenius acids and bases.

Answer 15

Acid: Produces H+ ions in aqueous solutions
Base: Produces OH- ions in aqueous solutions

Question 16

dentify Brønsted–Lowry acids and bases and their conjugates.

Answer 16

Acid: a proton downer
Base: a proton accepter
Conjugate acid-base pairs: an acid and a base that differ from each other only in the presence or absence of a proton

Question 17

Write equations for neutralization reactions.

Answer 17

Double displacement

AB + CD —> CB + AD

Question 18

Write equations for the reactions of acids with metals and with metal oxides.

Answer 18

Acid reaction with a metal has a product of Hydrogen gas (h2)

Acid reaction with metal oxide has a product of water (h2o)

Question 19

Use acid–base titration to determine the concentration of an unknown solution (e.g., determine
the molarity of a specified volume of one reactant when it requires a specified volume of a
specified concentration of another reactant to reach the equivalence point.)

Answer 19

Titration: A technique to determine the concentration of a solution by using a solution of known concentration

Given Va, Ma, and Vb

V reactant A x M reactant A = moles of reactant A

Moles A —-> moles B—-Moles/volumes—-> molarity B

Question 20

Given the concentration of hydroxide ion, calculate the concentration of hydronium ion and vice-versa.

Answer 20

With a given [H3O+]

OH- = 1.0x10^-14/ Given [H3O+]

With a given [OH-]

H3O+ = 1.0x10^-14/ Given [OH-]

Question 21

Given the pH or pOH of a solution, calculate the hydronium ion concentration or hydroxide ion
concentration.

Answer 21

Calculating [H3O+] from pH

[H3O+]= 10^-pH

Calculating [OH-] from pOH

[OH-] = 10^-pOH

Question 22

Buffer

Answer 22

A buffer is A solution that resists in changes pH. It does this by neutralizing added acid or base

-buffer consists of significant amount of either a weak acid and its conjugate base or a weak base and its conjugate acid

Question 23

pH scale of acidity

Answer 23

ph<7 acidic solution
ph>7 basic solution
ph= 7 neutral

Question 24

[H3O+] & [OH-] rules

Answer 24

In a neutral solution; [H3O+] = [OH-] = 1.0 x 10^-7M
In an acidic solution; [H3O+] > 1.0 x 10^-7M, [OH-] < 1.0 x 10^-7M
In a basic solution; [H3O+] < 1.0 x 10^-7M, [OH-] > 1.0 x 10^-7M
In all aqueous solution; [H3O+] [OH-] = Kw = 1.0 x 10^-14

Question 25

Calculating pH from [H3O+]
Calculating pOH from [OH-]

Answer 25

pH = -log[H3O+]
pOH = -log[OH-]

Question 26

Concentration of Ions in solution

EX: Find Mg and Cl of MgCl2 1.00 M

Answer 26

Convert
1 mol Mg 2+/ 1 mol MgCl2
2 mol Cl -/ 1 mol MgCl2

1mol MgCl2 x 1 mol Mg 2+/ 1 mol MgCl2 = 1.00 M Mg 2+

1 mol MgCl2 x 2 mol Cl -/ 1 mol MgCl2 = 2.00 M Cl-