Exams › JEE Main › Chemistry

Which of the following combinations will liberate hydrogen gas?

1. Zn metal and NaOH(aq)
2. Au metal and NaCN(aq) in the presence of air
3. Cu metal and conc. HNO3
4. Fe metal and conc. HNO3

Correct answer: Zn metal and NaOH(aq)

Solution

Zinc, being amphoteric, dissolves in NaOH to form sodium zincate and evolves H2 gas.

Related JEE Main Chemistry questions

• Which statement correctly describes how chemical reactivity changes down the group for alkali metals and halogens?
• Which of the following is a true peroxide?
• When zeolite, a hydrated sodium aluminium silicate, is used with hard water, which ions from the water replace the sodium ions in the zeolite?
• Among the following carbonates, which one is the least thermally stable?
• The solubility of carbonates falls as we move down the magnesium group because there is a reduction in the
• Which of the following salts fails to give any colour in a flame test?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →