Given, K=1.8×10−5,C=0.01M
We know that K=Cα2
So 18×10−6=10−2α2
18×10−6=α2
α=√18×10−2=3√2×10−2
α=4.2×10−2
α=0.042
Hence , degree of ionization is 0.042
[H+]=Cα=0.01(0.042)
[H+]=42×10−5 M