Compare Bond Enthalpy and Acidity of H2Se and H2Te

❓ Question

Given below are two statements:

Statement I:

$$H_2Se$$

is more acidic than

$$H_2Te$$

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Statement II:

$$H_2Se$$

has higher bond enthalpy for dissociation than

$$H_2Te$$

In light of the above statements, choose the correct answer:

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is false but Statement II is true
4. Statement I is true but Statement II is false

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🖼 Question Image

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✍️ Short Explanation

This problem is based on:

👉 Acidic character of hydrides
👉 Bond enthalpy trend
👉 Group 16 hydrides.

Main idea:

$$\boxed{{\displaystyle \text{Acidity increases down the group}}}$$

because bond strength decreases down the group.

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🔷 Step 1 — Trend of Acidity in Group 16 Hydrides 💯

Hydrides of group 16:

$$H_2O < H_2S < H_2Se < H_2Te$$

Acidity increases down the group because:

✔ Atomic size increases

✔ $H-E$ bond becomes weaker

✔ H$^+$ release becomes easier

Thus:

$$\boxed{ H_2Te \text{ is more acidic than } H_2Se }$$

Hence:

Statement I is FALSE.

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🔷 Step 2 — Bond Enthalpy Trend

Down the group:

$$\boxed{ \text{Bond enthalpy decreases} }$$

because atomic size increases.

Therefore:

$$H-Se \text{ bond}$$

is stronger than:

$$H-Te \text{ bond}$$

Thus:

$$\boxed{ H_2Se \text{ has higher bond enthalpy than } H_2Te }$$

Hence:

Statement II is TRUE.

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🔷 Step 3 — Final Conclusion

✔ Statement I → False

✔ Statement II → True

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🔷 Step 4 — JEE Trap Alert 🚨

❌ Electronegativity trend directly apply kar dena

❌ Acidity ko bond strength se relate na karna

❌ Group trend ulta yaad kar lena

Remember:

$$\boxed{ \text{Weaker } H-E \text{ bond} \Rightarrow \text{Stronger acid} }$$

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✅ Final Answer

$$\boxed{{\displaystyle \text{Statement I is false but Statement II is true}}}$$

(Option 3)

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📚 Related Topics

• MOI of Combined Bodies Using Parallel Axis
• Van’t Hoff Factor Shortcut for Percentage Dissociation
• Quadratic Equation Roots Reciprocal Relation Trick