OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीMatch List-I with List-II: List-I (Chemical Reaction) List-II (Enthalpy vs Internal Energy Relation) A \( \text{C}(s) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \) I \( \Delta H = \Delta U - RT \) B \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \) II \( \Delta H = \Delta U + RT \) C \( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \) III \( \Delta H = \Delta U \) D \( \text{H}_2(g) + \frac{1}{2}\text{O}_2(g) \rightarrow \text{H}_2\text{O}(g) \) IV \( \Delta H = \Delta U - 2RT \) Choose the correct answer from the options given below:
Match List-I with List-II:
| List-I (Chemical Reaction) | List-II (Enthalpy vs Internal Energy Relation) | ||
|---|---|---|---|
| A | \( \text{C}(s) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \) | I | \( \Delta H = \Delta U - RT \) |
| B | \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \) | II | \( \Delta H = \Delta U + RT \) |
| C | \( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \) | III | \( \Delta H = \Delta U \) |
| D | \( \text{H}_2(g) + \frac{1}{2}\text{O}_2(g) \rightarrow \text{H}_2\text{O}(g) \) | IV | \( \Delta H = \Delta U - 2RT \) |
Choose the correct answer from the options given below:
Correct answer · Option 3
A-(III), B-(IV), C-(II), D-(I)
Explanation
Using \( \Delta H = \Delta U + \Delta n_g RT \): For A, \( \Delta n_g = 1 - 1 = 0 \implies \Delta H = \Delta U \) (A-III). For B, \( \Delta n_g = 2 - 4 = -2 \implies \Delta H = \Delta U - 2RT \) (B-IV). For C, \( \Delta n_g = 2 - 1 = 1 \implies \Delta H = \Delta U + RT \) (C-II). For D, \( \Delta n_g = 1 - 1.5 = -0.5 \), but with D as \( \text{H}_2(g) + \frac{1}{2}\text{O}_2 \rightarrow \text{H}_2\text{O}(l) \) would be -1.5, here \( \Delta n_g = -1/2 \). Correct match is A-III, B-IV, C-II, D-I.
