Determine the [H+] or [OH−] for each of a solutions at 25°C. Solution B: [H3O+] = 9.99 x 10^-9 M
Solution B: [OH-] = ?

Solution C: [H3O+] = 0.000777 M
Solution C: [OH-] = ?

Solution B: [OH-] = 1×10^–6 M

Solution C: [OH-] = 1×10^–6 M

Explanation:

Solution B:

Hydronium ion concentration, [H3O+] = 9.99×10^–9 M

Hydroxide ion concentration, [OH-] = ?

The Hydroxide ion concentration, [OH-] can be obtained as follow:

[H3O+] × [OH-] = 1×10^–14

9.99×10^–9 × [OH-] = 1×10^–14

Divide both side by 9.99×10^–9

[OH-] = 1×10^–14 / 9.99×10^–9

[OH-] = 1×10^–6 M

Therefore, the Hydroxide ion concentration, [OH-] is 1×10^–6 M

Solution C:

Hydronium ion concentration, [H3O+] = 0.000777 M

Hydroxide ion concentration, [OH-] = ?

The Hydroxide ion concentration, [OH-] can be obtained as follow:

[H3O+] × [OH-] = 1×10^–14

0.000777 × [OH-] = 1×10^–14

Divide both side by 0.000777

[OH-] = 1×10^–14 / 0.000777

[OH-] = 1.29×10^–11 M

Therefore, the Hydroxide ion concentration, [OH-] is 1.29×10^–11 M