1
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

Ozone is formed by the reaction

$$ \mathrm{O}_{2(g)}+\mathrm{O}_{(g)} \rightarrow \mathrm{O}_{3(g)}, \Delta \mathrm{H}=-107.2 \mathrm{~kJ} . $$

Given $\mathrm{O}=0$ bond energy is $498.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$, the average bond energy of ozone is:

A

$302.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$

B

$520.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$

C

$120.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$

D

$201.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$

2
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

$\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ for a reaction are $35.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $83.6 \mathrm{~J} \mathrm{~K}^{-1}$ respectively. Assuming that $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ do not vary with temperature, the reaction is spontaneous when:

A

$\mathrm{T}<425 \mathrm{~K}$

B

$\mathrm{T}<350 \mathrm{~K}$

C

$\mathrm{T}>425 \mathrm{~K}$

D

$T>298 \mathrm{~K}$

3
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The heat of combustion of carbon to $\mathrm{CO}_2$ is $-393.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

The heat released on the formation of 35.2 g of $\mathrm{CO}_2$ by combustion of C is:

A

+215 kJ

B

-315 kJ

C

-325 kJ

D

+620 kJ

4
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
Two moles of an ideal gas at 1 bar pressure and 298 K is expanded into vacuum to double the volume. The work done is :
A
2 J
B
0 J
C
1.5 J
D
10 J

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