Question

Amongst the following, the total number of compounds whose aqueous solution turns red litmus paper blue is ___

KCN $K_{2}S{O}_4$ $(N{H}_4{)}_2{C}_2{O}_4$ $NaCl$ $Zn(N{O}_3{)}_2$ $FeC{l}_3$ $K_{2}C{O}_3$ $N{H}_{4}N{O}_3$
$LiCN$

Answer 1

Basic salt solutions will have pH > 7. These will change the colour of litmus paper from red to blue

Here, $KCN,K_{2}C{O}_3$ and $LiCN$ are the only basic salts. So, the answer will be 3.