Question

moles of HCl should be added to 1 L aqueous solution of HCl of pH=3, in order to decrease its pH to 2.

• A. 0.009
• B. 1
• C. 0.001

Answer 1

The correct option is A 0.009

Mole of HCl of pH=3 in 1 L is 0.001
Mole of HCl of pH=2 in 1 L is 0.01

Therefore, mole of HCl to be added in HCl of pH=3 is
= 0.01-0.001
= 0.009 mole