Question

The dissociation constant of a weak monoprotic acid, which is $0.01\%$ ionised in $1.00M$ solution, is

• A. $1×10^{−8}$
• B. $1×10^{−4}$
• C. $1×10^{−6}$
• D. $10^{−5}$

Answer 1

Answer: (A)

$K=\frac{{Î\pm }^{2}C}{1−Î\pm };1−Î\pm ≈1$
$∴K={Î\pm }^{2}C={\left[\frac{0.01}{100}\right]}^2×1$
$=1×10^{−8}$