Question

For a given aqueous solution at ${25}^{o}C$ which of the following is correct regarding the nature of solution:

• A. Acidic if $\left[H^{+}\right]<\sqrt{K_w}$
• B. Alkaline if $\left[H^{+}\right]<\sqrt{K_w}$
• C. Acidic if $\left[H^{+}\right]>\sqrt{K_w}$
• D. Neutral if $\left[H^{+}\right]=\sqrt{K_w}$

Answer 1

Answer: (B), (C), (D)

Neutral if $\left[H^{+}\right]=\sqrt{K_w}$

$\left[H^{+}\right]\left[O{H}^{-}\right]=K_w$
$\left[H^{+}\right]=\left[O{H}^{-}\right]$ in neutral solution.
So, solution will be neutral if
$\left[H^{+}\right]=\sqrt{K_w}$
In alkaline solution ,
$\left[H^{+}\right]<\left[O{H}^{-}\right]$
So, $\left[H^{+}\right]<\sqrt{K_w}$
In acidic solution ,
$\left[H^{+}\right]>\left[O{H}^{-}\right]$
So, $\left[H^{+}\right]>\sqrt{K_w}$