1
JEE Main 2023 (Online) 1st February Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Which element is not present in Nessler's reagent?

A
Mercury
B
Iodine
C
Potassium
D
Oxygen
2
JEE Main 2023 (Online) 1st February Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : $$\mathrm{Cu^{2+}}$$ in water is more stable than $$\mathrm{Cu^{+}}$$.

Reason (R) : Enthalpy of hydration for $$\mathrm{Cu^{2+}}$$ is much less than that of $$\mathrm{Cu^{+}}$$.

In the light of the above statements, choose the correct answer from the options given below :

A
(A) is correct but (R) is not correct
B
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
C
(A) is not correct but (R) is correct
D
Both (A) and (R) are correct and (R) is the correct explanation of (A)
3
JEE Main 2023 (Online) 1st February Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Highest oxidation state of Mn is exhibited in $$\mathrm{Mn_2O_7}$$. The correct statements about $$\mathrm{Mn_2O_7}$$ are

(A) Mn is tetrahedrally surrounded by oxygen atoms.

(B) Mn is octahedrally surrounded by oxygen atoms.

(C) Contains Mn-O-Mn bridge.

(D) Contains Mn-Mn bond.

Choose the correct answer from the options given below :

A
A and C only
B
A and D only
C
B and C only
D
B and D only
4
JEE Main 2023 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

When $$\mathrm{Cu}^{2+}$$ ion is treated with $$\mathrm{KI}$$, a white precipitate, $$\mathrm{X}$$ appears in solution. The solution is titrated with sodium thiosulphate, the compound $$\mathrm{Y}$$ is formed. $$\mathrm{X}$$ and $$\mathrm{Y}$$ respectively are :

A
$$\mathrm{X=CuI_2}$$ $$\mathrm{Y=Na_2S_4O_6}$$
B
$$\mathrm{X=Cu_2I_2}$$ $$\mathrm{Y=Na_2S_4O_6}$$
C
$$\mathrm{X=CuI_2}$$ $$\mathrm{Y=Na_2S_2O_3}$$
D
$$\mathrm{X=Cu_2I_2}$$ $$\mathrm{Y=Na_2S_4O_5}$$
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