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

Which one of the following options represents the decreasing order of oxidation number of the central atom in:

$$\mathrm{Cr}_2 \mathrm{O}_7^{2-}, \mathrm{Cr} \mathrm{O}_2^{-}, \mathrm{MnO}_4^{-}, \mathrm{BrO}_3^{-}$$

A
$\mathrm{CrO}_2^{-}>\mathrm{BrO}_3^{-}>\mathrm{Cr}_2 \mathrm{O}_7^{2-}>\mathrm{MnO}_4^{-}$
B
$\mathrm{MnO}_4^{-}>\mathrm{CrO}_2^{-}>\mathrm{Cr}_2 \mathrm{O}_7^{2-}>\mathrm{BrO}_3^{-}$
C
$\mathrm{BrO}_3^{-}>\mathrm{CrO}_2^{-}>\mathrm{MnO}_4^{-}>\mathrm{Cr}_2 \mathrm{O}_7^{2-}$
D
$\mathrm{MnO}_4^{-}>\mathrm{Cr}_2 \mathrm{O}_7^{2-}>\mathrm{BrO}_3^{-}>\mathrm{CrO}_2^{-}$
2
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0

COMEDK 2025 Morning Shift Chemistry - d and f Block Elements Question 1 English

What is the spin only magnetic moment of the metal ion in $\mathbf{P}$ and the oxidation number of Sulphur in the oxidised product Z ?

A
$\mu=0 \quad$ Oxidation number $=+4$
B
$\mu=5.00 \mathrm{BM} \quad$ Oxidation number $=0$
C
$\mu=5.92 \mathrm{BM} \quad$ Oxidation number $=+2$
D
$\mu=1.732 \mathrm{BM} \quad$ Oxidation number $=+6$
3
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0
The conductivity of 0.01 M solution of $\mathrm{CH}_3 \mathrm{COOH}$ at 298 K is $1.65 \times 10^{-4} \mathrm{Scm}^{-1}$ What is the $\mathrm{pK}_{\mathrm{a}}$ value of the acid if $\lambda^0\left(\mathrm{H}^{+}\right)$and $\lambda^0\left(\mathrm{CH}_3 \mathrm{COO}\right)^{-1}$ are $349.1 \mathrm{Scm}^2 \mathrm{~mol}^{-1}$ and $40.9 \mathrm{Scm}^2 \mathrm{~mol}^{-1}$ respectively?
A
4.73
B
1.87
C
3.47
D
2.95
4
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0

Two statements, one Assertion (A) and the other Reason (R) are given. Choose the correct option.

Assertion: 2-aminoethanoic acid and p-aminobenzene sulphonic acid can exist as Zwitter ions while p-aminobenzoic acid cannot.

Reason: When the acid group is a relatively strong proton donor and the $-\mathrm{NH}_2$ group is sufficiently basic it can accept a $\mathrm{H}^{+}$ion from the acid group to form the dipolar ion.

A
Both A and R are correct and R is the correct explanation of A .
B
A is correct but R is wrong.
C
A is wrong but R is correct.
D
Both A and R are correct but R is not the correct explanation of A .
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