Question

Complete the following table, which lists information about the measured acid dissociation constants of three unknown weak acids. Note: be sure each number you put in the table has the correct number of significant digits. к, relative strength acid 8.515 A (Choose one) ? X 11 2. x 10 B (Choose one) 7,04 (Choose one)

Answer 1

Acid A

pKa = 8.515

Ka = 10^-pKa = 10^-(8.515)​​​​ = 3.05 x 10^-9

Acid B

Ka = 2 x 10^-11

pKa = -log[Ka] = -log(2 x 10^-11) = 10.699

Acid C

pKa = 7.04

Ka = 10^-pKa = 10^-(7.04)​​​​ = 9.120 x 10^-8

It is well known that the relative strength of acid depends upon the dissociation constant of the acid. Higher the Ka value, higher the acidic strength.

since the decreasing order of acids, A, B and C is as

C (9.120 x 10^-8) > A ( 3.05 x 10^-9) > B (2 x 10^-11)

Thus, the relative strength of acids are as

C > A  > B