Question

What is the pH of a 0.085 M solution of nitrous acid (HNO2) that has a Ka of 4.5 × 10^-4?

2.21


5.33


3.35


4.42

I am not the best at working through the problems, but I came to A, 2.21, given the concentration and Ka.

Answer 1

HNO2 <> H+ + NO2-

ka=x^2/(.085-x)
.085ka-ka*x=x^2
x^2+4.5*x*e-4 -.085*4.5e-4=0 >>> http://www.math.com/students/calculators/source/quadratic.htm
x=0.0059637498737628745
p(x)=2.22448058

Answer 2

Great, thank you for confirming my answer!!

Answer 3

Is this K12 AP Chemistry? I need some help myself on the matter.