1
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Identify the reagents to be used to complete the given reaction.

COMEDK 2025 Afternoon Shift Chemistry - Haloalkanes and Haloarenes Question 2 English

A
$\mathrm{A}=\mathrm{Br}_2 / \mathrm{CCl}_4 \quad \mathrm{~B}=$ alc. $\mathrm{KOH} \quad \mathrm{C}=\mathrm{NaNH}_2 \quad \mathrm{D}=$ Red hot Fe tube
B
$\mathrm{A}=\mathrm{HBr} \quad \mathrm{B}=$ alc. $\mathrm{KOH} \quad \mathrm{C}=\mathrm{CaC}_2 \quad \mathrm{D}=$ Red hot Ni tube
C
$A=\mathrm{CHBr}_3 \quad B=$ aq. $\mathrm{KOH} \quad C=$ Conc. $\mathrm{HI} \quad D=$ Red hot Pd tube
D
$\mathrm{A}=\mathrm{Br}_2 / \mathrm{CCl}_4 \quad \mathrm{~B}=$ aq. $\mathrm{KOH} \quad \mathrm{C}=$ Conc. $\mathrm{H}_2 \mathrm{SO}_4 \quad \mathrm{D}=$ Red hot Cu tube
2
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

What is the standard electrode potential at 298 K for the reaction: $\mathrm{Cu}^{2+}+1 \mathrm{e}-\rightarrow \mathrm{Cu}^{+1}$ ?

Given: $\mathrm{E}_0 \mathrm{Cu}^{+1} / \mathrm{Cu}=0.5 \mathrm{~V} \quad \& \quad \mathrm{E}_0 \mathrm{Cu}^{+2} / \mathrm{Cu}=0.335 \mathrm{~V}$

A
0.34V
B
0.17V
C
0.492V
D
0.410V
3
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0
Which one of the following molecules attains greater stability on formation of its diatomic monovalent anion?
A
$\mathrm{C}_2$
B
$\mathrm{O}_2$
C
$\mathrm{N}_2$
D
$\mathrm{F_2}$
4
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

The Standard Reduction potential at $25^{\circ} \mathrm{C}$ for $\left(\mathrm{MnO}_4\right)^{-1} / \mathrm{H}^{+}$is +1.49 V . The $\mathrm{E}^0$ values for four Metal ions :

(a). $\mathrm{Co}^{3+} / \mathrm{Co}^{2+}$

(b). $\mathrm{Cr}^{3+} / \mathrm{Cr}$

(c). $\mathrm{Au}^{3+} / \mathrm{Au}$ and

(d). $\mathrm{Ag}^{+} / \mathrm{Ag}$

are $+1.81 \mathrm{~V},-0.74 \mathrm{~V},+1.50 \mathrm{~V}$ and +0.8 V respectively. Identify two of them which cannot be oxidised by $\left(\mathrm{MnO}_4\right)^{-1} / \mathrm{H}^{+}$

A
a & d
B
a & c
C
b & d
D
b & c
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