Question

The first and second dissociation constants of an acid, $H_{2}A$ are $1.0\times {10}^{-5}$ and $5.0\times {10}^{-10}$ respectively. The overall dissociation constant of the acid will

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

$K_a=K_{a1}\times K_{a2}=(1.0\times {10}^{-5})\times (5.0\times {10}^{-10})=5.0\times {10}^{-15}$