Question

What is the pH when 15.0 g of the strong nitric acid (HNO₃, molar mass= 63.02 g/mole) is added to 825 mL of total solution?

Solution:

Answer 1

Solution.

$\lbrack HNO_3\rbrack=15.0g\sdot\dfrac{mol}{63.02g}\sdot\dfrac{1}{0.825L}=0.285M;$

$HNO_3(aq)\to H^+(aq)+NO_3^-(aq);$

$\lbrack H^+\rbrack=\lbrack HNO_3\rbrack=0.285M.$

$pH=-lg\lbrack H^+\rbrack=-lg0.285=0.55.$

Answer: $pH=0.55.$