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 ▸

Explain why Magnesium has a greater second ionisation energy than strontium


How does a catalyst and increasing temperature affect the rate of reaction?


By considering the mechanism of the two step reaction of butanone and NaBH4 followed by dilute acid, explain why the product has no effect on plane polarised light.


Why is the melting temperature of Magnesium higher than that of Sodium?