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

The frequency of photon which is emitted during a transition of electron of $\mathrm{He}^{+}$ion from fifth energy level to third energy level will be:

A

$1.34 \times 10^{-14} \mathrm{~s}^{-1}$

B

$9.39 \times 10^{14} \mathrm{~s}^{-1}$

C

$2.34 \times 10^{14} \mathrm{~s}^{-1}$

D

$8.29 \times 10^{-14} \mathrm{~s}^{-1}$

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

$$ \text { Match the reactions in List I with the final products formed as given in List II. } $$

$$
\text { List I }
$$
$$
\text { List II }
$$
W $$
\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_3 \frac{(\text { i }) \mathrm{CrO}_3+\left(\mathrm{CH}_3 \mathrm{CO}\right)_2 \mathrm{O}}{(\text { ii }) \mathrm{H}_3 \mathrm{O}+\text { heat }} \rightarrow
$$
P $$
\mathrm{R}_2 \mathrm{CO}
$$
X $$
\mathrm{RCOOC}_2 \mathrm{H}_5 \frac{(\text { i) } D I B A L-H}{(\text { ii }) \mathrm{H}_2 \mathrm{O}} \rightarrow
$$
Q $$
\mathrm{C}_6 \mathrm{H}_5 \mathrm{COCH}_3
$$
Y $$
R C N \frac{(i) R-\mathrm{Mg}-\mathrm{X} / \text { dry ether }}{(i i) \mathrm{H}_3 \mathrm{O}^{+}} \rightarrow
$$
R $$
\mathrm{C}_6 \mathrm{H}_5 \mathrm{CHO}
$$
Z $$
\mathrm{C}_6 \mathrm{H}_5 \mathrm{COCl}+\left(\mathrm{CH}_3\right)_2 \mathrm{Cd} \text { in dry ether → }
$$
S $$
\mathrm{RCHO}
$$
A

$$ W-Q \quad X-P \quad Y-S \quad Z-R $$

B

$$ W-R \quad X-P \quad Y-Q \quad Z-S $$

C

$$ W-R \quad X-S \quad Y-P \quad Z-Q $$

D

$$ W-S \quad X-R \quad Y-Q \quad Z-P $$

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

$$ \text { The product formed in the following reaction is: } $$

COMEDK 2026 Afternoon Shift Chemistry - Aldehyde and Ketone Question 1 English

A

COMEDK 2026 Afternoon Shift Chemistry - Aldehyde and Ketone Question 1 English Option 1

B

COMEDK 2026 Afternoon Shift Chemistry - Aldehyde and Ketone Question 1 English Option 2

C

COMEDK 2026 Afternoon Shift Chemistry - Aldehyde and Ketone Question 1 English Option 3

D

COMEDK 2026 Afternoon Shift Chemistry - Aldehyde and Ketone Question 1 English Option 4

4
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

How many molecules of $\mathrm{CO}_2(\mathrm{~g})$ are obtained on reaction of 24 grams of methane with 4 moles of oxygen?

A

$3.011 \times 10^{23}$

B

$12.044 \times 10^{23}$

C

$6.022 \times 10^{23}$

D

$9.033 \times 10^{23}$