Which of the following solutions would have the most basic pH? Assume that they are all 0.10 M in acid at 25C. The acid is followed by its Ka value. Group of answer choices HClO2, 1.1 × 10-2 HCHO2, 1.8 × 10-4 HCN, 4.9 × 10-10 HNO2, 4.6 × 10-4 HF, 3.5 × 10-4

Explanation:

Given:

Ka of HClO2 = 1.1 × 10-2

Ka of HCHO2 = 1.8 × 10-4

Ka of HCN = 4.9 × 10-10

Ka of HNO2 = 4.6 × 10-4

Ka of HF = 3.5 × 10-4

All at a concentration of 0.1 M

A.

HA --> H+ + A-

Ka = [H+] × [A-]/[HA]

[H+] = [A-] = x

[HClO2] = 0.1 M

HClO2 --> ClO2^- + H+

1.1 × 10-2 = x^2/0.1

x = sqrt(1.1 × 10^-3

= 0.033 M

pH = -log[H+]

= 1.48

B.

HA --> H+ + A-

Ka = [H+] × [A-]/[HA]

[H+] = [A-] = x

[HCHO2] = 0.1 M

HCHO2 --> CHO2^- + H+

1.8 × 10-4 = x^2/0.1

x = sqrt(1.8 × 10^-5)

= 0.0042 M

pH = -log[H+]

= 2.37

C.

HA --> H+ + A-

Ka = [H+] × [A-]/[HA]

[H+] = [A-] = x

[HCN] = 0.1 M

HCN --> CN- + H+

4.9 × 10-10 = x^2/0.1

x = sqrt(4.9 × 10-11)

= 0.000007 M

pH = -log[H+]

= 5.16

D.

HA --> H+ + A-

Ka = [H+] × [A-]/[HA]

[H+] = [A-] = x

[HNO2] = 0.1 M

HNO2 --> NO2^- + H+

4.6 × 10-4 = x^2/0.1

x = sqrt(4.6 × 10-5)

= 0.0068 M

pH = -log[H+]

= 2.17

E.

HA --> H+ + A-

Ka = [H+] × [A-]/[HA]

[H+] = [A-] = x

[HF] = 0.1 M

HF --> F- + H+

3.5 × 10-4 = x^2/0.1

x = sqrt(3.5 × 10-5)

= 0.0059 M

pH = -log[H+]

= 2.23

a) pH = 1.48

b) pH = 2.37

c) pH = 5.16

d) pH = 2.17

e) pH = 2.33

HCN is most basic because;

smallest Ka

Highest pH value = 5.16

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.