1
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0
The first ionisation enthalpy of Al in $\mathrm{kJ} \mathrm{mol}^{-1}$ is: [Given the first ionisation enthalpy of $\mathrm{Na}, \mathrm{Mg}$ and Si in $\mathrm{kJ} \mathrm{mol}^{-1}$ are 497,738 and 787 respectively]
A
769
B
578
C
488
D
857
2
COMEDK 2025 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0
Choose the coordination compound which does not exhibit Optical activity.
A
cis $-\left[\mathrm{PtCl}_2(\mathrm{en}) 2\right]^{2+}$
B
$\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$
C
trans $-\left[\mathrm{CoCl}_2(\mathrm{en})_2\right]^{+}$
D
cis $-\left[\mathrm{CoCl}_2(\mathrm{en})_2\right]^{+}$
3
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
4
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
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