JEE Main · 2024 · 05 Apr 2024 · Shift 2 · d and f Block Elements

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is ____.

Ti^{2 +}, Cr^{2 +}

and

V^{2 +}

Answer: (C)

Solution

T i^{2 +}

C r^{2 +}

and

V^{2 +}

are all strong reducing agents — each is readily oxidised to its more stable

+ 3

state — and each is capable of reducing

H^{+}

H_{2}

, e.g.

2 C r_{(a q)}^{2 +} + 2 H_{(a q)}^{+} \to 2 C r_{(a q)}^{3 +} + H_{2} (g)

All three ions qualify, so the number is 3.

JEE Main · 2024 · 05 Apr 2024 · Shift 2 · Single correct option