Need help with quarantine homework

Question

If we were to add 0.02 moles of HCl and 0.01 moles of KOH to make up a

1 liter solution, what ions would be remaining after reaction and what

would be the pH of that liter of solution?

Answer 1

First, write the balanced equation:

HCl(aq) + NaOH(aq) ==> NaCl(aq) + H2O(l)

Next, use the moles of each that are present to find what is left over.

moles HCl = 0.02

moles NaOH = 0.01

moles HCl left over = 0.01 moles HCl

moles NaOH left over = 0 moles NaOH

moles NaCl formed = 0.01 moles NaCl

moles H2O formed = 0.01 moles H₂O

Ions remaining after reaction:

H⁺ from the HCl and from H2O

Cl^- from the HCl and the NaCl

Na⁺ from the NaCl

OH^- from H₂O

pH of solution:

pH = -log [H⁺]

Since [H⁺] = 0.01 mol H+/L = 0.01 M

-log 0.01 = 2

pH = 2