COMEDK2015Chemistryp Block Elements (Group 15, 16, 17 & 18)
Which of the following chemicals does not liberate hydrogen gas on reaction with aluminium metal?
Options
- ADil. sulphuric acid
- BAqueous sodium hydroxide
- CDil. hydrochloric acid
- DConc. nitric acid
Correct answer
D. Conc. nitric acid
Step-by-step solution
Dil. and conc. HNO ₃ has no effect on Al . Aluminium is rendered passive by nitric acid due to the formation of a thin film of oxide ( Al ₂ O ₃ ) on its surface. 2 Al +6 HNO ₃ (conc.) Al ₂ O ₃+6 NO ₂+3 H ₂ O Aluminium reacts with H ₂ SO ₄ to libreate H ₂ gas. 2 Al +3 H ₂ SO ₄ Al ₂ ( SO ₄ )₃+3 H ₂ Aluminium also reacts with aqueous alkali and liberates dihydrogen. 2 Al (s)+2 NaOH (a q)+6 H ₂ O (l) 2 Na [ Al ( OH )₄ ](a q)+3 H ₂(g) Aluminium dissolves in dil. HCl and liberates dihydrogen. 2 Al (s)+6 HCl (a q) 2 Al ³⁺