STUDY GUIDE Flashcards
Convert between pressure units.
Pa = 1n/m^2
1atm = 101325 Pa
1atm = 760 mmHg
1torr = 1mmHg
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.
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
Use the combined gas law to determine the P, V, or T under a specified set of conditions
P1V1/T1 = P2V2/T2
Use the ideal gas law to determine P, V, T, or n.
PV = nRT
Use the ideal gas law to determine the volume or moles of gaseous products or reactants in
chemical reactions involving gases
n = PV/RT
V= (nRT)/P
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.
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+…
Perform stoichiometric calculations for gases in chemical reactions
Vgas —PV=nRT—> moles of gas—->moles of other reactant or product
Calculate mass percent and use mass percent in calculations as a conversion factor.
( Mass solute/ Mass solution ) x 100
Calculate molarity and use molarity in calculations as a conversion factor.
M (molarity) = moles solute/Liter solution
Solve solution dilution problems.
M1V1 = M2V2
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.
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
Calculate molality.
m = Moles of solute / kg solvent
Calculate the freezing point and boiling point of a given solution.
-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
Identify common acids and bases and describe their key characteristics.
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
dentify Arrhenius acids and bases.
Acid: Produces H+ ions in aqueous solutions
Base: Produces OH- ions in aqueous solutions
dentify Brønsted–Lowry acids and bases and their conjugates.
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
Write equations for neutralization reactions.
Double displacement
AB + CD —> CB + AD
Write equations for the reactions of acids with metals and with metal oxides.
Acid reaction with a metal has a product of Hydrogen gas (h2)
Acid reaction with metal oxide has a product of water (h2o)
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.)
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
Given the concentration of hydroxide ion, calculate the concentration of hydronium ion and vice-versa.
With a given [H3O+]
OH- = 1.0x10^-14/ Given [H3O+]
With a given [OH-]
H3O+ = 1.0x10^-14/ Given [OH-]
Given the pH or pOH of a solution, calculate the hydronium ion concentration or hydroxide ion
concentration.
Calculating [H3O+] from pH
[H3O+]= 10^-pH
Calculating [OH-] from pOH
[OH-] = 10^-pOH
Buffer
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
pH scale of acidity
ph<7 acidic solution
ph>7 basic solution
ph= 7 neutral
[H3O+] & [OH-] rules
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
