A student added solid K2O to a 750.0 mL volumetric flask. The solid was dissolved in water and then the flask filled with water to the mark. This formed 750.0 mL of the initial KOH solution. 20.0 mL of the initial solution was transferred to another flask and diluted to 200.0 mL. The pH of the diluted solution was 14.22.

Question

A student added solid K2O to a 750.0 mL volumetric flask. The solid was dissolved in water and then the flask filled with water to the mark. This formed 750.0 mL of the initial KOH solution. 20.0 mL of the initial solution was transferred to another flask and diluted to 200.0 mL. The pH of the diluted solution was 14.22.
a) What is the concentration of hydroxide ion is the diluted solution? 
I found this to be 1.66M becaue PH + POH =14 so POH=-.22 then since pOH=-log(OH-) concentration of hydroxide ions would be 1.66M

(b) What is the concentration of hydroxide ion in the original solution? 
M

(c) What mass of K2O was added to the first flask?

Anonymous · Answer

Yes