Question

$M{n}_2{O}_7$ 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)

$M{n}_2{O}_7$ dissolves in water to give permanganic acid which is purple in colour.
$M{n}_2{O}_7+H_{2}O⟶\underset{\text{ Purple }}{2HMn{O}_4}$