1
JEE Main 2023 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Choose the correct set of reagents for the following conversion.

trans $$\left(\mathrm{Ph}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}\right) \rightarrow \operatorname{cis}\left(\mathrm{Ph}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}\right)$$

A
$$\mathrm{Br_2,alc\cdot KOH,NaNH_2,H_2}$$ Lindlar Catalyst
B
$$\mathrm{Br_2,aq\cdot KOH,NaNH_2,Na}$$ (Liq NH$$_3$$)
C
$$\mathrm{Br_2,alc\cdot KOH,NaNH_2,Na}$$ (Liq NH$$_3$$)
D
$$\mathrm{Br_2,aq\cdot KOH,NaNH_2,H_2}$$ Lindlar Catalyst
2
JEE Main 2023 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $$\mathrm{n=4}$$ to $$\mathrm{n}=2$$ of $$\mathrm{He}^{+}$$ spectrum

A
$$\mathrm{n}=3$$ to $$\mathrm{n}=4$$
B
$$\mathrm{n}=2$$ to $$\mathrm{n}=1$$
C
$$\mathrm{n}=1$$ to $$\mathrm{n}=2$$
D
$$\mathrm{n}=1$$ to $$\mathrm{n}=3$$
3
JEE Main 2023 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Which one of the following statements is correct for electrolysis of brine solution?

A
$$\mathrm{O}_{2}$$ is formed at cathode
B
$$\mathrm{H}_{2}$$ is formed at anode
C
$$\mathrm{Cl}_{2}$$ is formed at cathode
D
$$\mathrm{OH}^{-}$$ is formed at cathode
4
JEE Main 2023 (Online) 31st January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Cobalt chloride when dissolved in water forms pink colored complex $$\underline{\mathrm{X}}$$ which has octahedral geometry. This solution on treating with conc $$\mathrm{HCl}$$ forms deep blue complex, $$\underline{\mathrm{Y}}$$ which has a $$\underline{\mathrm{Z}}$$ geometry. $$\mathrm{X}, \mathrm{Y}$$ and $$\mathrm{Z}$$, respectively, are

A
$$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}, \mathrm{Y}=\left[\mathrm{CoCl}_{4}\right]^{2-}, \mathrm{Z}=$$ Tetrahedral
B
$$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}, \mathrm{Y}=\left[\mathrm{CoCl}_{6}\right]^{3-}, \mathrm{Z}=$$ Octahedral
C
$$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4} \mathrm{Cl}_{2}\right]^{+}, \mathrm{Y}=\left[\mathrm{CoCl}_{4}\right]^{2-}, \mathrm{Z}=$$ Tetrahedral
D
$$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}, \mathrm{Y}=\left[\mathrm{CoCl}_{6}\right]^{3-}, \mathrm{Z}=$$ Octahedral
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