Question

Which of the following statement(s) is/are correct about the ionic product of water?

• A. $K_i$ (ionization constant of water) $<K_w$ (ionic product of water)
• B. $p{K}_i>p{K}_w$
• C. At ${25}^{\circ }C,K_i=1.8\times {10}^{-14}$
• D. Ionic product of water at ${10}^{\circ }C$ is ${10}^{-14}$

Answer 1

Answer: (A), (B)

$K_i$ (ionization constant of water) $<K_w$ (ionic product of water)
$p{K}_i>p{K}_w$

For water,
$K_i=\frac{\left[H^{+}\right]\left[O{H}^{-}\right]}{\left[H_{2}O\right]}$

$K_w=\left[H^{+}\right]\left[O{H}^{-}\right]$, so

$K_i$ (ionization constant of water) $<K_w$ (ionic product of water).

$(p{K}_i=-log{K}_i)>(p{K}_w=-log{K}_w)$.

At ${25}^{o}C,K_w={10}^{-14}$. As temperature decreases, value of $K_w$ also decreases from ${10}^{-14}$.