Answer to Question #160655 in General Chemistry for Tzuyu

Question

Calculate the pH of the following salts:a) 0.12 M NaNO₂ b) 0.10 M CH₃NH₃Cl c) .45 M NaOCl?

Answer 1

a)NaNO$_2$ is a mixture of HNO$_2$ and NaOH

P$_k$ a of HNO$_2$ =3.15

$pH= 7+1/2[Pka+logC]\\ p^H=7+1/2[3.15+log(0.12)]\\ p^H=8.16$

b)CH3NH3Cl is a salt of strong acid and weak base.

pH=7-1/2[Pkb+logC]

p^H=7-1/2[3.34+log(0.1)]\\

p^H= 5.83

c) NaOCl is a salt of strong base and weak acid

pH= 7+1/2[Pka+logC]\\

p^H=7+1/2[7.53+log(0.45)]\\

p^H=10.59