Question

What is the pH of a 0.055 M solution of sodium cyanide? The K_a value for hydrocyanic acid is 6.2 x 10^-10.

Select one:

a. 10.08

b. 8.77

c. 10.97

d. 5.23

e. 3.03

What is the pH of a mixture containing 0.33 M HNO₂ and 0.20 M NaNO₂? (K_a for HNO₂ = 4.5 x 10^-4)

Select one:

a. 7.8

b. 3.57

c. 3.13

d. 1.22

e. 3.35

What is the molar solubility of Zn²⁺ in a solution that is buffered at a pH of 4.00? The K_sp for Zn(OH)₂ is 3 x 10^-17.

Select one:

a. 6 x 10^-23 mol/L

b. 7 x 10^-4 mol/L

c. 3000 mol/L

d. 3 x 10^-7 mol/L

e. 3 x 10^-17 mol/L

Answer 1

0 HA - H+ + A- I 0.055 E 0.055 Kar [H+7[A-] 6.2x10-10 n2 oooss-n 0.ossonno.oss. x 2 = 3.41xlol x 5.84466-6 pre = -log [hot] - log (5.84x108) - 15.23