Question

Which of the following statement about hydrogen is incorrect ?

• A. Hydrogen never acts as cation in ionic salts
• B. Hydronium ion, $H_3{O}^{+}$ exists freely in solution
• C. Dihydrogen does not act as a reducing agent
• D. Hydrogen has three isotopes of which tritium is the most common

Answer 1

Answer: (C), (D)

Hydrogen exist as a hydride $\left(H^{-}\right)$in ionic salt.
Most abundant form of hydrogen is protium.
Dihydrogen reduces some metal ions in aqueous solution and oxides of metals (less active than iron) into corresponding metals.
$H_2(g)+P{d}^2+(aq)⟶Pd(s)+2H^{+}(aq)$
$y{H}_2(g)+MxOy(s)⟶xM(s)+y{H}_{2}O(\ell )$