What volume of HCl gas at 25â—¦ C and 1 atm should be bubbled into 375 mL of a 0.680 M aqueous solution of HClO4 so that the pH of the resulting solution is 0? Assume that all the HCl dissolves and that

the volume of the solution does not change with the addition of HCl.

1 answer

How many mols do we have in the HClO4. That's M x L = 0.680*.375 = about 0.250 but you need to be more accurate than that.
How much acid do you need to add to make pH = 0. pH = 0 means 1.0M H^+.
mols desired = M x L = 1.0 x 0.375L = 0.375 mols.

Difference is 0.375-0.250 = about 0.125 mols.
Use PV = nRT to solve for volume of HCl gas at the conditions listed.