JEE Main levelNumerical answerDifficulty 2 of 3ia100
What is the degree of ionisation of 0.100MCHX3COOH (Ka=1.8×10−5) in a solution that is also 0.0500M in HCl? Use the exact quadratic. Give α×103 to two decimals.
Numerical answer type, tolerance 0.02.
Answer: 0.36
Let x be [CHX3COOX−]: x(0.0500+x)/(0.100−x)=1.8×10−5, i.e. x2+0.050018x−1.8×10−6=0, so x=3.60×10−5M. α=x/0.100=0.00036, so α×103=0.36.