Answer to Question #143111 in Inorganic Chemistry for om

Question

Given the following sets of information, calculate the requested quantities for each problem.

1. [H3O+] = 4.1 x 10-4 M. Find pH, and [OH-]
2. [OH-] = 6.6 x 10-9 M. Find pOH, and [H3O+]
3. pH = 9.0. Find [H3O+], [OH-] and pOH
4. pOH = 12.5. Find [OH-], and [H3O+]
5. pOH = 7.0. Find [H3O+], [OH-] and pH 

Answer 1

Solution.

$pH = -lg[H3O^+]$

$pOH = -lg[OH^-]$

$pH + pOH = 14$

$pH = 14-pOH$

$pOH = 14-pH$

1.

pH = 3.39

pOH = 10.61

$[OH^-] = 10^{-pOH}$

$[OH^-] = 2.45\times 10^{-11}$

2.

pOH = 8.18

pH = 5.82

$[H3O^+] =10^{-pH}$

$[H3O^+] = 1.51 \times 10^{-6}$

3.

pOH = 5.0

$[H3O^+] = 10^{-9}$

$[OH^-] = 10^{-5}$

4.

pH = 1.5

$[H3O^+] = 3.16 \times 10^{-2}$

$[OH^-] = 3.16 \times 10^{-13}$

5.

pH = 7.0

$[H3O^+] = 10^{-7}$

$[OH^-] = 10^{-7}$

Answer:

1.

pH = 3.39

$[OH^-] = 2.45\times 10^{-11}$

2.

pOH = 8.18

$[H3O^+] = 10^{-9}$

3.

pOH = 5.0

$[H3O^+] = 10^{-9}$

$[OH^-] = 10^{-5}$

4.

$[H3O^+] = 3.16 \times 10^{-2}$

$[OH^-] = 3.16 \times 10^{-13}$

5.

pH = 7.0

$[H3O^+] = 10^{-7}$

$[OH^-] = 10^{-7}$