Question

Which of the following has the smallest bond angle?

• A. \( \text{H}_2\text{O} \)
• B. \( \text{H}_2\text{S} \)
• C. \( \text{H}_2\text{Se} \)
• D. \( \text{H}_2\text{Te} \)

Hint:

Smaller central atoms (like oxygen) result in smaller bond angles due to stronger lone pair repulsion.

Answer 1

The Correct Option is A

Step 1: Understanding bond angles.
The bond angle in a molecule is influenced by the size of the central atom. As the size of the atom increases, the bond angle generally decreases due to the increased repulsion between lone pairs of electrons. Step 2: Analysis of options.
(A) \( \text{H}_2\text{O} \): Water has a bent shape with a bond angle of approximately 104.5°, which is the smallest among the options due to lone pair repulsion.
(B) \( \text{H}_2\text{S} \): Hydrogen sulfide has a bond angle of around 92°, which is larger than water's bond angle.
(C) \( \text{H}_2\text{Se} \): Hydrogen selenide has a bond angle of around 91°, slightly larger than H₂S.
(D) \( \text{H}_2\text{Te} \): Hydrogen telluride has a bond angle of around 90°, which is the largest among the given molecules.
Step 3: Conclusion.
The correct answer is (A) because \( \text{H}_2\text{O} \) has the smallest bond angle due to its smaller central atom and stronger lone pair repulsion.