If ionic product of water is K w=10-16 at 4° C, then a solution with pH =7.5 at 4° C will

Question

If ionic product of water is K w=10-16 at 4° C, then a solution with pH =7.5 at 4° C will (A) Turn blue litmus red (B) Turn red litmus blue (C) Be neutral to litmus (D) Be alkaline

Tardigrade Admin · Accepted Answer

K w=10-16 or [ H +][ OH -]=10-16 ∵ [ H +]=[ OH -] for pure water ⇒ [ H +]=10-8 ⇒ pH =8 is neutral ∴ pH =7.5 < 8 is acidic and hence turns blue litmus paper red.

Q. If ionic product of water is $K_{w} = 1 0^{- 16}$ at $4^{\circ} C$ , then a solution with $p H = 7.5$ at $4^{\circ} C$ will

Turn blue litmus red

Turn red litmus blue

Be neutral to litmus

Be alkaline

$K_{w} = 1 0^{- 16}$
or $[H^{+}] [O H^{-}] = 1 0^{- 16}$
$∵ [H^{+}] = [O H^{-}]$ for pure water
$\Rightarrow [H^{+}] = 1 0^{- 8}$
$\Rightarrow p H = 8$ is neutral
$∴ p H = 7.5 < 8$ is acidic and hence turns blue litmus paper red.

Q. If ionic product of water is Kw​=10−16 at 4∘C, then a solution with pH=7.5 at 4∘C will