WAEC - Chemistry (2001 - No. 47)
Which of the following salt solutions will have a pH greater than 7?
NaCl(aq)
Na2CO3(aq)
Na2SO4(aq)
NaHSO4(aq)
Explanation
The pH of a solution of sodium carbonate is greater than 7 because it's a basic salt. When Na2CO3 is dissolved in water, it undergoes hydrolysis, which produces OH- ions, making the solution pH greater than 7.