Calculate the ph of a solution that is 0.295 m in sodium formate (nahco2) and 0.205 m in formic acid (hco2h). the ka of formic a

Question

MissTica

4 years ago

8

Calculate the ph of a solution that is 0.295 m in sodium formate (nahco2) and 0.205 m in formic acid (hco2h). the ka of formic a

cid is 1.77 ⋅ 10-4.

Chemistry

1 answer:

Evgesh-ka [11] · Answer 1 · 2021-12-08T01:56:54+03:00

Hello!

The chemical reaction for the dissociation of Formic Acid is the following:

HCOOH + H₂O ⇄ HCOO⁻ + H₃O⁺

From this reaction we can use the Henderson-Hasselbach equation to find the pH, but first we need to find the value for the pKa:

pKa=-log(Ka)=3,75

pH=pKa + log([HCOO⁻]/[HCOOH])

pH=3,75 + log (0,295/0,205)

pH= 3,90

Have a nice day!