1.

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 HClA. `11.30`B. `10.53`C. `2.70`D. `8.35`

Answer» Correct Answer - A
`20.0 mL "of" 0.01 M Ca (OH)_(2) "has" Ca(OH)_(2)`
`=20xx0.01` millimoles = 0.2 millimole
`:. OH^(-)` ions present `=2xx0.2` millimole
`=0.4` millimole
30.0 mL of 0.01 M HCl has HCl
`=30xx0.01` millimoles = 0.3 millimole
`:. H^(+)` ions present = 0.3 millimole
0.3 millimole `H^(+)` will neutralize 0.3 millimoe of `OH^(-)`. Hence, `OH^(-)` ions present after mixing = 0.1 millimole
Volume of solution = 20 +30 = 50 mL
Hence, molarity of `OH^(-)` ions `=(0.1)/(50)=2xx10^(-3)M`
`pOH = - log (2xx10^(-3))=3-0.30=2.70`
`:. pH = 14 - 2.70 = 11.30`


Discussion

No Comment Found

Related InterviewSolutions