1
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Given below a first order reaction in the gas phase

$$\mathrm{A}(\mathrm{g}) \rightarrow \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})$$

If the initial pressure of the system is $$\mathrm{P}_{\mathrm{i}}$$ and the total pressure at $$\mathrm{t}$$ seconds is $$\mathrm{P}_{\mathrm{t}}$$, the rate constant $$\mathrm{k}$$ for the reaction is:

A
$$ \mathrm{k}=\frac{2.303}{\mathrm{t}} \log \frac{\mathrm{P}_{\mathrm{i}}}{\mathrm{P}_{\mathrm{t}}} $$
B
$$ \mathrm{k}=\frac{2.303}{\mathrm{t}} \log \frac{\mathrm{P}_{\mathrm{i}}}{\left(2 \mathrm{P}_{\mathrm{i}}-\mathrm{P}_{\mathrm{t}}\right)} $$
C
$$ \mathrm{k}=\frac{2.303}{\mathrm{t}} \log \frac{\mathrm{P}_{\mathrm{i}}}{\left(2 \mathrm{P}_{\mathrm{i}}+\mathrm{x}\right)} $$
D
$$ \mathrm{k}=\frac{2.303}{\mathrm{t}} \log \frac{\mathrm{P}_{\mathrm{i}}}{\left(\mathrm{P}_{\mathrm{i}}+\mathrm{x}\right)} $$
2
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Which of the following reactions is an example for incomplete combustion?

A
COMEDK 2024 Afternoon Shift Chemistry - Hydrocarbons Question 4 English Option 1
B
COMEDK 2024 Afternoon Shift Chemistry - Hydrocarbons Question 4 English Option 2
C
COMEDK 2024 Afternoon Shift Chemistry - Hydrocarbons Question 4 English Option 3
D
COMEDK 2024 Afternoon Shift Chemistry - Hydrocarbons Question 4 English Option 4
3
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

The $$\mathrm{E}^{\circ}$$ values of $$\mathrm{A} . \mathrm{B}$$ and $$\mathrm{C}$$ are given. Which element/(s) is/(are) good for coating the surface of iron to prevent corrosion? Given: $$[\mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^0=-0.44 \mathrm{~V} ; \quad \mathrm{E}_{\mathrm{A}^{2+} / \mathrm{A}}^0=-2.37 \mathrm{~V} ; \quad \mathrm{E}_{\mathrm{B}^{2+} / \mathrm{B}}^0=-0.15 \mathrm{~V} ; \quad \mathrm{E}_{\mathrm{C}^{2+} / \mathrm{C}}^0=+0.34 \mathrm{~V}]$$

A
Element C only
B
Elements B and C
C
Element B only
D
Element A only
4
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

4-methyl benzamide (A) on reaction with ethanolic solution of $$\mathrm{KOH}$$ and bromine gives another compound (B). The compound (B) on treatment with benzoyl chloride gives compound (C). Identify the correct structure of compound (C) from the following.

A
COMEDK 2024 Afternoon Shift Chemistry - Carboxylic Acids and Its Derivatives Question 3 English Option 1
B
COMEDK 2024 Afternoon Shift Chemistry - Carboxylic Acids and Its Derivatives Question 3 English Option 2
C
COMEDK 2024 Afternoon Shift Chemistry - Carboxylic Acids and Its Derivatives Question 3 English Option 3
D
COMEDK 2024 Afternoon Shift Chemistry - Carboxylic Acids and Its Derivatives Question 3 English Option 4
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