Acid determine H3O and OH

Question

Part A

For the strong acid solution 0.0750 M HCI, determine [H3O+] and [OH-].

Part B

For this solution determine pH.

Part C

For the strong acid solution 7.9×10⁻⁴ M HI, determine [H3O+] and [OH-].

Part D

For this solution determine pH.

Answer 1

A:

0.075 MHCl + H₂O ==> 0.075 M H₃O⁺ + 0.075 M Cl^-

[OH^-] = 1x10^-14 / 0.075 = 1.33x10^-13 M

B:

pH = -log [H₃O⁺] = -log 0.075 = 1.12

C:

7.9x10-4 M HI + H₂O ==> 7.9x10^-4 M H₃O⁺ + 7.9x10^-4 M I^-

[H₃O⁺] = 7.9x10^-4 M

[OH^-] = 1x10^-14 / 7.9x10^-4 = 1.27x10^-11 M

D:

pH = -log [H₃O⁺] = -log 7.9x10^-4 = 3.12