The correct order of acidity of hybrides of oxygen family

Options

A. `H_(2) O gt H_(2) S gt H_(2) Se gt H_(2) Te`
B. `H_(2) O lt H_(2) S lt H_(2) Se lt H_(2) Te`
C. `H_(2) S gt H_(2) O gt H_(2) Se gt H_(2) Te`
D. `H_(2) S lt H_(2) O lt H_(2) Se lt H_(2) Te`

Answer

To determine the correct order of acidity of the hydrides of the oxygen family (Group 16), we will analyze the hydrides: H2O (water), H2S (hydrogen sulfide), H2Se (hydrogen selenide), and H2Te (hydrogen telluride).

### Step-by-Step Solution:

1. **Identify the Hydrides**:
The hydrides of the oxygen family that we need to consider are:
- H2O (water)
- H2S (hydrogen sulfide)
- H2Se (hydrogen selenide)
- H2Te (hydrogen telluride)

2. **Understand Acidity**:
Acidity refers to the ability of a compound to donate protons (H+ ions). The easier it is for a compound to release H+, the stronger its acidity.

3. **Analyze Bond Strength**:
The bond strength of the H-X bond (where X is the group 16 element) decreases as we move down the group from oxygen to tellurium. This is due to the increase in atomic size and the corresponding decrease in bond dissociation energy:
- H-O bond in H2O is the strongest.
- H-S bond in H2S is weaker than H-O.
- H-Se bond in H2Se is weaker than H-S.
- H-Te bond in H2Te is the weakest.

4. **Order of Bond Dissociation Energy**:
The bond dissociation energies can be summarized as follows:
- H-O > H-S > H-Se > H-Te

5. **Relate Bond Strength to Acidity**:
Since weaker bonds are easier to break, the acidity increases as the bond strength decreases. Therefore, the order of acidity will be the reverse of the order of bond strength:
- H2Te > H2Se > H2S > H2O

6. **Final Order of Acidity**:
The correct order of acidity for the hydrides of the oxygen family is:
- H2Te (highest acidity) > H2Se > H2S > H2O (lowest acidity)

### Conclusion:
Thus, the correct order of acidity of the hydrides of the oxygen family is:
**H2Te > H2Se > H2S > H2O**