Question

$C{l}_2$ gas is obtained by various reactions but not by:

• A. $KMn{O}_4+\text{conc.}HCl\stackrel{\Delta }{\to }$
• B. $KCl+K_{2}C{r}_2{O}_7+\text{conc.}{H}_{2}S{O}_4\stackrel{\Delta }{\to }$
• C. $Mn{O}_2+\text{conc.}HCl\stackrel{\Delta }{\to }$
• D. $KCl+F_2\to$

Answer 1

Answer: (B)

$KCl+K_{2}C{r}_2{O}_7+\text{conc.}{H}_{2}S{O}_4\stackrel{\Delta }{\to }$

Chlorine gas can be obtained by the following reactions:

A). $2KMn{O}_4+16HCl\stackrel{\Delta }{\to }2KCl+2MnC{l}_2+8H_{2}O+5C{l}_2$

C). $Mn{O}_2+4HCl\stackrel{\Delta }{\to }MnC{l}_2+2H_{2}O+C{l}_2$

D). $2KCl+F_2\to 2KF+C{l}_2$

However, chlorine is not prepared by the action of concentrated sulfuric acid on a mixture of $KCl$ and potassium dichromate, as it will form chromyl chloride.

B). $4KCl+K_{2}C{r}_2{O}_7+3H_{2}S{O}_4\stackrel{\Delta }{\to }3K_{2}S{O}_4+\underset{chromylchloride}{2Cr{O}_{2}C{l}_2\uparrow }+3H_{2}O$

Hence, the reaction in option B does not produce chlorine.

Option B is correct.