Question

1)

A 1.31 L buffer solution consists of 0.301 M propanoic acid and 0.159 M sodium propanoate. Calculate the pH of the solution following the addition of 0.073 mol HCl. Assume that any contribution of the HCl to the volume of the solution is negligible. The Ka of propanoic acid is 1.34×10−5.

pH =

2)

Consider Kc for the following equilibrium given the info below.

2SO3(g)⇌2SO2(g)+O2(g)

0.20 mol SO3 is placed in a 1.00 L vessel at a high temperature and allowed to come to equilibrium at which time 0.0075 mol SO3 remains.

calculate Kc for this reaction

3)

calculate the equilibrium concentrations of all four species given these initial concentrations: [CO]=[H2O]=0.60M

EQUILIBRIUM CONCENTRATIONS (use 2 sig figs)

[CO]=

[H2O]=

[H2]=

[CO2]=

4)

calculate the equilibrium concentrations of all species when 0.250 M benzoic acid, HC7H5O2, dissolves in water, Kc=6.31 x 10^-5

(use 3 sig figs)

[HC7H5O2]=

[H3O+]=

[C7H5O2-]=

What is the pH?

5)

Calculate the pH of solution made from dissolving 1.00 mol acetic acid (HC2H3O2) in enough water to make 1.00 L of solution

ka=1.8x10^-5

please help me. thank you.

Answer 1

Following formulas will be used for solving the problems-

Concentration = No. of moles present in 1L of solution

pH = pka + log [Conjugate Base]/[Acid]

pKa = -log[Ka]