1
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
The enthalpies of combustion of $\mathrm{H}_2, \mathrm{C}$ (graphite) and $\mathrm{C}_2 \mathrm{H}_6(\mathrm{~g})$ are $-286.0,-394.0$ and $-1560.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $25^{\circ} \mathrm{C}$ and 1 atm pressure. The enthalpy of formation of ethane is :
A
$-97.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
B
$-86.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
C
$-92.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
D
$-78.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
2
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0
Which of the following is the most stable free radical?
A
$\left(\mathrm{C}_6 \mathrm{H}_5\right)_2 \dot{\mathrm{C}} \mathrm{H}$
B
$\dot{\mathrm{C}} \mathrm{H}_3$
C
$\left(\mathrm{CH}_3\right)_3 \dot{\mathrm{C}}$
D
$\mathrm{CH}_2=\dot{\mathrm{C}} \mathrm{H}$
3
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0

What are the intermediates formed during the reactions $A$ and $B$ ?

A. Reimer-Tiemann reaction.

B. Dehydration of alcohols in the slow rate determining step.

A
COMEDK 2025 Evening Shift Chemistry - Alcohol, Phenols and Ethers Question 1 English Option 1
B
COMEDK 2025 Evening Shift Chemistry - Alcohol, Phenols and Ethers Question 1 English Option 2
C
COMEDK 2025 Evening Shift Chemistry - Alcohol, Phenols and Ethers Question 1 English Option 3
D
COMEDK 2025 Evening Shift Chemistry - Alcohol, Phenols and Ethers Question 1 English Option 4
4
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0

Arrange the following in the increasing order of their covalent character.

$\mathrm{CaF}_2 ; \mathrm{CaCl}_2 ; \mathrm{CaBr}_2 ; \mathrm{CaI}_2$

A
$\mathrm{CaF}_2<\mathrm{CaI}_2<\mathrm{CaBr}_2<\mathrm{CaCl}_2$
B
$\mathrm{CaF}_2<\mathrm{CaCl}_2<\mathrm{CaI}_2<\mathrm{CaBr}_2$
C
$\mathrm{CaCl}_2<\mathrm{CaF}_2<\mathrm{CaBr}_2<\mathrm{CaI}_2$
D
$\mathrm{CaF}_2<\mathrm{CaCl}_2<\mathrm{CaBr}_2<\mathrm{CaI}_2$
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