Question

(1) Identify each of the following half-reactions as either an oxidation half-reaction or a reduction half-reaction. half-reaction identification Cr3+(aq) + 3e — Cr(s) Al(s)—+A13+(aq) + 3e (2) Write a balanced equation for the overall redox reaction. Use smallest possible integer coefficients. <> Submit Answer Retry Entire Group 9 more group attempts remaining

Answer 1

1)

Reduction: Addition of electron

Oxdation: Loss of electron

$Cr^{3+}(aq)+ 3e^- \rightarrow Cr(s) ...........Reduction$

$Al(s)\rightarrow Al(aq) +3e^- ...........oxidation$

2)

Oxiadtion half reaction + Reduction half reaction=>

Cr3+ + Al(s) + Cr(s) + A13+ (aq) ----> Balanced redox reaction

BALANACING IN ACIDIC MEDIUM:

i. Balance the metal first

ii. Balance oxygen atom by adding H2O on that side in which it has less number of oxygen atom

iii. To balance hydrogen atom, add twice H+ on the other side of H2O added in above step

iv. Balance charge by adding e- on required side

3)

$NO_3^-\rightarrow NO$

$=>NO_3^-\rightarrow NO + 2H_2O$

$=>NO_3^- +4H^+\rightarrow NO + 2H_2O$

Oxidation state of N channges from +5 to +2