Calculate the pH of a 0.0131 mol dm^-3 solution of calcium hydroxide at 10 degrees centigrade.

Multiply by 2 because calcium hydroxide = Ca(OH)2 so 2 x [OH-] per molecule.[OH-] = 0.0131 x 2 = 0.0262
Insert [OH-] value into the equilibrium equation along with the value of Kw at 10 degrees centigrade 2.93 x 10^-15 (from data tables). This gives the value for [H=].[H+] = (Kw/[OH-] ) = 2.93 x 10^-15 / 0.0262 = 1.118 x 10^-13
Finally, insert [H+] value into pH equation.pH = -log (1.118 x 10^-13) = 12.95

EW

Related Chemistry A Level answers

All answers ▸

Give the molecular formula of benzene. Give the Kekule structure of benzene and then explain why this structure is not correct. Give the accepted structure for benzene (5 marks).


How can aldehydes and ketones be distinguished?


Why does Benzene require a catalyst to react with Bromine whereas Phenol does not?


What is a racemic mixture and why is it not optically active?