Determine the pH of the solution that results from the addition of 20.00 mL of 0.01 M Ca `(OH)_(2)` to 30.00 mL of 0.01 M HCI

Options

A. 11.3
B. 10.53
C. `2.70`
D. 8.35

Answer

A

Explanation

Millimoles of `H^(+) = 30 xx 0.01 = 0.3`
Millimoles of `OH^(-) = 20 xx 0.01 xx 2 = 0.4`
Remaining millimoles of `OH^(-) = 0.4 - 0.3 = 0.1`
`[OH^(-)] = (0.1)/(50)` or `2 xx 10^(-3)`
So, `pOH = 2.6999 rArr pH = 14 - 2.6999 = 11.30`.