Question

An aqueous solution contains 0.25 M nitrous acid. One Liter of this solution could be converted into a buffer by the addition of: (Assume that the volume remains constant as each substance is added.) 0.26 mol HNO3 0.13 mol HNO3 0.063 mol Ca(OH)2 0.26 mol KNO2 0.25 mol KClO4 Submit Answer

Answer 1

0.26 mol KNO₂

Step-by-step explanation:

A buffer is defined as the mixture of a weak acid with its conjugate base or vice versa.

Nitrous acid (HNO₂) is a weak acid with pka of 3.3. Its conjugate base is NO₂⁻. KNO₂ in solution produce K⁺ + NO₂⁻. That means right answer is:

0.26 mol KNO₂.

I hope it helps!