Question

In acidic medium, \(K_2 Cr _2 O _7\) shows oxidising action as represented in the half reaction

\(Cr _2 O ^{2-}_7 + XH ^+ + Ye ^- \rightarrow 2A + ZH_2 O\)

X, Y, Z and A are respectively are: 

(1) 8, 6, 4 and \(Cr _2 O _3\)

(2) 14, 7, 6 and \(Cr ^{3+}\)

(3) 8, 4, 6 and \(Cr _2 O _3\)

(4) 14, 6, 7 and \(Cr ^{3+}\)

Answer 1

(4) 14, 6, 7 and \(Cr ^{3+}\)

The balanced reaction is,

\(Cr_2 O ^{2-} _7 +14 H ^+ + 6 e^- \rightarrow 2 Cr ^{3+} + 7 H_2 O\)

X = 14

Y = 6

A = 7