Question

What is the pH if 0.0256 g of Potassium Hydroxide are dissolved in enough water to make .212 liters of solution? (Hint: you are

solving for poH first and then finding pH)

Answer 1

pH= 11.332

Further explanation

KOH⇒K⁺+OH⁻

KOH(MW=56,1056 g/mol)

mol KOH :

`\tt (0.0256)/(56.1056)=4.56* 10^(-4)`

molarity KOH :

`\tt (4.56* 10^(-4))/(0.212)=2.15* 10^(-3)`

[OH⁻]=[KOH]=2.15 x 10⁻³

pOH=-log[OH⁻]

`\tt pOH=-log~2.15* 10^(-3)\\\\pOH=3-log~2.15\\\\pOH=2.668`

pH+pOH=14

`\tt pH=14-2.668=\boxed{\bold{11.332}}`