Question

Least stable Hydride is?

• A. HF
• B. HCl
• C. BeH₂
• D. NaH

Answer 1

The Correct Option is C

The stability of hydrides is an important concept in chemistry, especially when discussing compounds containing hydrogen. Let's analyze the given options to determine the least stable hydride.

1. HF (Hydrogen Fluoride):

   Hydrogen fluoride is a simple binary compound of hydrogen and fluorine. It forms strong hydrogen bonds, making it relatively stable.

2. HCl (Hydrogen Chloride):

   Hydrogen chloride is also relatively stable as a gas and forms hydrochloric acid in water, which is stable due to aqueous stability.

3. BeH₂ (Beryllium Hydride):

   Beryllium hydride is considered the least stable among the given options. It is not stable in pure form under standard conditions and requires specific handling due to its reactivity. Its instability stems from the electron deficiency of beryllium and the weak Be-H bonds.

4. NaH (Sodium Hydride):

   Sodium hydride is an ionic compound that is quite stable at room temperature as long as it is kept dry. It decomposes at higher temperatures.

Based on the analysis, BeH₂ (Beryllium Hydride) is the least stable hydride among the options given. The primary reason for this instability is the covalent character with weak Be-H bonds and the electron deficiency around the beryllium atom, which does not allow for the formation of strong bonds like the other hydrides.

To conclude, the correct answer is BeH₂.