Chapter 9

Why is the position of hydrogen not justified in the periodic table?

Discuss the various methods used for the production of dihydrogen.

Write balanced equations for the following processes: (a) Electrolysis of water (b) Treatment of sodium hydride with water (c) Treatment of calcium with water (d) Production of \(\mathrm{CH}_{4}\) from a carbide

Why are more hydrides covalent rather than ionic? Explain.

Give reasons for the following: (a) \(\mathrm{H}^{-}\) is larger than He. (b) NaH is strongly hydrophillic but \(\mathrm{GeH}_{4}\) is weakly hydrophillic. (c) Acetylene reacts with active metals to liberate hydrogen. (d) Ionic hydrides are more dense than the parent metal while interstitial hydrides are less dense than the parent metal. (e) Palladium is used as a catalyst for hydrogenation.

Write complete balanced equations for the following: (a) \(\mathrm{Al}+\mathrm{NaOH}+\mathrm{H}_{2} \mathrm{O}(\mathrm{b}) \mathrm{LiAlH}_{4}+\mathrm{SnCl}_{4}\) (c) \(\mathrm{CaH}_{2}+\mathrm{CH}_{3} \mathrm{OH}\) (d) \(\mathrm{Cd}\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)+\mathrm{LiAlH}_{4}\)

Discuss the spin isomers of hydrogen. Is it possible to obtain pure para- hydrogen?

What is heavy water? How is it obtained? What are its pronerties?

Differentiate between atomic dihydrogen and nascent hydrogen.