Question

0.1M acetic acid gets 1% ionised. If it ionises 10 times then concentration of [H+] will be.? 1) 0.001 2) 0.01 3) 0.05 4) 0.1

Answer 1

Dear student,
Given: concentration c=0.1M , ${\alpha }_1=1\%$ ,${\alpha }_2=10$
CH₃COOH$\rightleftharpoons$CH₃COO^-+ H+
initial 0.1 0 0
after ionization 0.1(1-$\alpha$) c $\alpha$ c $\alpha$

When ionization is 10 times
[H⁺]=c$\alpha$₂

=$$\begin{gathered} 0.1\times \frac{0.1\times 10}{100} \\ c\alpha \end{gathered}$$

[H⁺]=0.001

I hope this is easy! .There can be an alternative method where first K_a is calculated using first ionization , then put same K_a for another ionization to get concentration of [H⁺]
Regards