Question

$Mn_2O_7$ dissolves in water to give an acid. The colour of the acid is

• A. green
• B. blue
• C. purple
• D. red

Answer 1

Answer: (C)

purple

Answer 2

$Mn _{2} O _{7}$ dissolves in water to give permanganic acid which is purple in colour.
$Mn _{2} O _{7}+ H _{2} O \longrightarrow \underset{\text { Purple }}{2 HMn O _{4}}$