Medium MCQ +4 / -1 PYQ · JEE Mains 2024

A and B formed in the following reactions are:

$$\begin{aligned} & \mathrm{CrO}_2 \mathrm{Cl}_2+4 \mathrm{NaOH} \rightarrow \mathrm{A}+2 \mathrm{NaCl}+2 \mathrm{H}_2 \mathrm{O}, \\ & \mathrm{A}+2 \mathrm{HCl}+2 \mathrm{H}_2 \mathrm{O}_2 \rightarrow \mathrm{B}+3 \mathrm{H}_2 \mathrm{O} \end{aligned}$$

  1. A $\mathrm{A}=\mathrm{Na}_2 \mathrm{Cr}_2 \mathrm{O}_7, \mathrm{~B}=\mathrm{CrO}_5$
  2. B $\mathrm{A}=\mathrm{Na}_2 \mathrm{CrO}_4, \mathrm{~B}=\mathrm{CrO}_5$ Correct answer
  3. C $\mathrm{A}=\mathrm{Na}_2 \mathrm{Cr}_2 \mathrm{O}_4, \mathrm{~B}=\mathrm{CrO}_4$
  4. D $\mathrm{A}=\mathrm{Na}_2 \mathrm{Cr}_2 \mathrm{O}_7, \mathrm{~B}=\mathrm{CrO}_3$

Solution

<p>$$\mathrm{Cr{O_2} + 4NaOH \to \mathop {N{a_2}Cr{O_4}}\limits_{(A)} + 2NaCl + 2{H_2}O}$$</p> <p>$$\mathrm{N{a_2}Cr{O_4} + 2{H_2}{O_2} + 2HCl \to \mathop {Cr{O_5}}\limits_{(B)} + \mathop {2NaCl}\limits_{(Mis\sin g\,from\,balanced\,equation)} + 3{H_2}O}$$</p>

About this question

Subject: Chemistry · Chapter: p-Block Elements · Topic: Group 13: Boron Family

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