Question

Imagine you have a 0.000 324 M solution of sulfuric acid. If you have 233 mL of that solution, what is the number of moles of

a) sulfide ions?

b) hydrogen ions?

c) What is the pH of the solution

d) what is the pOH of the solution?

Answer 1

sulfuric acid have formula H2SO4
number of mole of H2SO4 = (molarity of H2SO4)*(volume of solution in L)
= 0.000324*0.233
= (7.55*10^-5) mole

a)
1 mol of H2SO4 give 1 mol of Sulfide ion
number of mole of sulfide ions = (number of mole of H2SO4)
= (7.55*10^-5) mole
b)
1 mol of H2SO4 give 2 mol of hydrogen ion
number of mole of hydrogen ion = 2*(number of mole of H2SO4)
= 2*(7.55*10^-5) mole
= (1.51*10^-4) mole
c)
[H+] = (number of mole of hydrogen ion)/(volume of solution in L)
= (1.51*10^-4)/0.233
= (6.48*10^-4) M
pH = -log[H+]
= -log(6.48*10^-4)
= 3.19
d)
pOH = 14 - pH
= 14 - 3.19
= 10.81