Q.

Which of the following salts will give highest pH in water              [2014]

1 KCl  
2 NaCl  
3 Na2CO3  
4 CuSO4  

Ans.

(3)

Na2CO3, which is a salt of NaOH (strong base) and H2CO3 (weak acid), will produce a basic solution with pH greater than 7.