Balancing of Redox Reactions
CHXI08:REDOX REACTIONS

315082 For the reaction:
\(\mathrm{\mathrm{NH}_{3}+\mathrm{OCl}^{-} \longrightarrow \mathrm{N}_{2} \mathrm{H}_{4}+\mathrm{Cl}^{-}}\)in basic medium, the coefficients \(\mathrm{\mathrm{NH}_{3}, \mathrm{OCl}}\) and \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}}\) for the balanced equation are respectively.

1 \(\mathrm{2,2,2}\)
2 \(\mathrm{2,2,1}\)
3 \(\mathrm{2,1,1}\)
4 \(\mathrm{4,4,2}\)
CHXI08:REDOX REACTIONS

315083 How many electrons are involved in the following redox reaction?
\(\rm{\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}}\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left( {{\rm{Unbalanced}}} \right)\)

1 3
2 4
3 6
4 5
CHXI08:REDOX REACTIONS

315084 The number of electrons required to balance the following equation
\(\rm{\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+e^{-} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{NO} \text { is }}\)

1 5
2 4
3 3
4 2
CHXI08:REDOX REACTIONS

315085 In the following balanced reaction,
\(\rm{{\text{XMnO}}_{\text{4}}^{\text{ - }}{\text{ + Y}}{{\text{C}}_{\text{2}}}{\text{O}}_{\text{4}}^{{\text{2 - }}} \rightleftharpoons {\text{XM}}{{\text{n}}^{{\text{2 + }}}}{\text{ + YC}}{{\text{O}}_{\text{2}}}{\text{ + }}\frac{{\text{Z}}}{{\text{2}}}{{\text{H}}_{\text{2}}}{\text{O}}}\)
values of X, Y and Z respectively are

1 2, 5, 16
2 8, 2, 5
3 5, 2, 16
4 5, 8, 4
CHXI08:REDOX REACTIONS

315086 Reaction of liquid hydrazine \(\mathrm{\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)}\) with chlorate ion \(\mathrm{\left(\mathrm{ClO}_{3}^{-}\right)}\)in basic medium produces nitric oxide gas and chloride ion in gaseous state. The balanced chemical equation for the reaction is

1 \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow \mathrm{NO}+3 \mathrm{Cl}^{-}+\mathrm{H}_{2} \mathrm{O}}\)
2 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+4 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
3 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
4 \(\mathrm{4 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 8 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
CHXI08:REDOX REACTIONS

315082 For the reaction:
\(\mathrm{\mathrm{NH}_{3}+\mathrm{OCl}^{-} \longrightarrow \mathrm{N}_{2} \mathrm{H}_{4}+\mathrm{Cl}^{-}}\)in basic medium, the coefficients \(\mathrm{\mathrm{NH}_{3}, \mathrm{OCl}}\) and \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}}\) for the balanced equation are respectively.

1 \(\mathrm{2,2,2}\)
2 \(\mathrm{2,2,1}\)
3 \(\mathrm{2,1,1}\)
4 \(\mathrm{4,4,2}\)
CHXI08:REDOX REACTIONS

315083 How many electrons are involved in the following redox reaction?
\(\rm{\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}}\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left( {{\rm{Unbalanced}}} \right)\)

1 3
2 4
3 6
4 5
CHXI08:REDOX REACTIONS

315084 The number of electrons required to balance the following equation
\(\rm{\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+e^{-} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{NO} \text { is }}\)

1 5
2 4
3 3
4 2
CHXI08:REDOX REACTIONS

315085 In the following balanced reaction,
\(\rm{{\text{XMnO}}_{\text{4}}^{\text{ - }}{\text{ + Y}}{{\text{C}}_{\text{2}}}{\text{O}}_{\text{4}}^{{\text{2 - }}} \rightleftharpoons {\text{XM}}{{\text{n}}^{{\text{2 + }}}}{\text{ + YC}}{{\text{O}}_{\text{2}}}{\text{ + }}\frac{{\text{Z}}}{{\text{2}}}{{\text{H}}_{\text{2}}}{\text{O}}}\)
values of X, Y and Z respectively are

1 2, 5, 16
2 8, 2, 5
3 5, 2, 16
4 5, 8, 4
CHXI08:REDOX REACTIONS

315086 Reaction of liquid hydrazine \(\mathrm{\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)}\) with chlorate ion \(\mathrm{\left(\mathrm{ClO}_{3}^{-}\right)}\)in basic medium produces nitric oxide gas and chloride ion in gaseous state. The balanced chemical equation for the reaction is

1 \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow \mathrm{NO}+3 \mathrm{Cl}^{-}+\mathrm{H}_{2} \mathrm{O}}\)
2 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+4 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
3 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
4 \(\mathrm{4 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 8 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
CHXI08:REDOX REACTIONS

315082 For the reaction:
\(\mathrm{\mathrm{NH}_{3}+\mathrm{OCl}^{-} \longrightarrow \mathrm{N}_{2} \mathrm{H}_{4}+\mathrm{Cl}^{-}}\)in basic medium, the coefficients \(\mathrm{\mathrm{NH}_{3}, \mathrm{OCl}}\) and \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}}\) for the balanced equation are respectively.

1 \(\mathrm{2,2,2}\)
2 \(\mathrm{2,2,1}\)
3 \(\mathrm{2,1,1}\)
4 \(\mathrm{4,4,2}\)
CHXI08:REDOX REACTIONS

315083 How many electrons are involved in the following redox reaction?
\(\rm{\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}}\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left( {{\rm{Unbalanced}}} \right)\)

1 3
2 4
3 6
4 5
CHXI08:REDOX REACTIONS

315084 The number of electrons required to balance the following equation
\(\rm{\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+e^{-} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{NO} \text { is }}\)

1 5
2 4
3 3
4 2
CHXI08:REDOX REACTIONS

315085 In the following balanced reaction,
\(\rm{{\text{XMnO}}_{\text{4}}^{\text{ - }}{\text{ + Y}}{{\text{C}}_{\text{2}}}{\text{O}}_{\text{4}}^{{\text{2 - }}} \rightleftharpoons {\text{XM}}{{\text{n}}^{{\text{2 + }}}}{\text{ + YC}}{{\text{O}}_{\text{2}}}{\text{ + }}\frac{{\text{Z}}}{{\text{2}}}{{\text{H}}_{\text{2}}}{\text{O}}}\)
values of X, Y and Z respectively are

1 2, 5, 16
2 8, 2, 5
3 5, 2, 16
4 5, 8, 4
CHXI08:REDOX REACTIONS

315086 Reaction of liquid hydrazine \(\mathrm{\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)}\) with chlorate ion \(\mathrm{\left(\mathrm{ClO}_{3}^{-}\right)}\)in basic medium produces nitric oxide gas and chloride ion in gaseous state. The balanced chemical equation for the reaction is

1 \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow \mathrm{NO}+3 \mathrm{Cl}^{-}+\mathrm{H}_{2} \mathrm{O}}\)
2 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+4 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
3 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
4 \(\mathrm{4 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 8 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
CHXI08:REDOX REACTIONS

315082 For the reaction:
\(\mathrm{\mathrm{NH}_{3}+\mathrm{OCl}^{-} \longrightarrow \mathrm{N}_{2} \mathrm{H}_{4}+\mathrm{Cl}^{-}}\)in basic medium, the coefficients \(\mathrm{\mathrm{NH}_{3}, \mathrm{OCl}}\) and \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}}\) for the balanced equation are respectively.

1 \(\mathrm{2,2,2}\)
2 \(\mathrm{2,2,1}\)
3 \(\mathrm{2,1,1}\)
4 \(\mathrm{4,4,2}\)
CHXI08:REDOX REACTIONS

315083 How many electrons are involved in the following redox reaction?
\(\rm{\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}}\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left( {{\rm{Unbalanced}}} \right)\)

1 3
2 4
3 6
4 5
CHXI08:REDOX REACTIONS

315084 The number of electrons required to balance the following equation
\(\rm{\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+e^{-} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{NO} \text { is }}\)

1 5
2 4
3 3
4 2
CHXI08:REDOX REACTIONS

315085 In the following balanced reaction,
\(\rm{{\text{XMnO}}_{\text{4}}^{\text{ - }}{\text{ + Y}}{{\text{C}}_{\text{2}}}{\text{O}}_{\text{4}}^{{\text{2 - }}} \rightleftharpoons {\text{XM}}{{\text{n}}^{{\text{2 + }}}}{\text{ + YC}}{{\text{O}}_{\text{2}}}{\text{ + }}\frac{{\text{Z}}}{{\text{2}}}{{\text{H}}_{\text{2}}}{\text{O}}}\)
values of X, Y and Z respectively are

1 2, 5, 16
2 8, 2, 5
3 5, 2, 16
4 5, 8, 4
CHXI08:REDOX REACTIONS

315086 Reaction of liquid hydrazine \(\mathrm{\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)}\) with chlorate ion \(\mathrm{\left(\mathrm{ClO}_{3}^{-}\right)}\)in basic medium produces nitric oxide gas and chloride ion in gaseous state. The balanced chemical equation for the reaction is

1 \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow \mathrm{NO}+3 \mathrm{Cl}^{-}+\mathrm{H}_{2} \mathrm{O}}\)
2 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+4 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
3 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
4 \(\mathrm{4 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 8 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
CHXI08:REDOX REACTIONS

315082 For the reaction:
\(\mathrm{\mathrm{NH}_{3}+\mathrm{OCl}^{-} \longrightarrow \mathrm{N}_{2} \mathrm{H}_{4}+\mathrm{Cl}^{-}}\)in basic medium, the coefficients \(\mathrm{\mathrm{NH}_{3}, \mathrm{OCl}}\) and \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}}\) for the balanced equation are respectively.

1 \(\mathrm{2,2,2}\)
2 \(\mathrm{2,2,1}\)
3 \(\mathrm{2,1,1}\)
4 \(\mathrm{4,4,2}\)
CHXI08:REDOX REACTIONS

315083 How many electrons are involved in the following redox reaction?
\(\rm{\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}}\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\left( {{\rm{Unbalanced}}} \right)\)

1 3
2 4
3 6
4 5
CHXI08:REDOX REACTIONS

315084 The number of electrons required to balance the following equation
\(\rm{\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+e^{-} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{NO} \text { is }}\)

1 5
2 4
3 3
4 2
CHXI08:REDOX REACTIONS

315085 In the following balanced reaction,
\(\rm{{\text{XMnO}}_{\text{4}}^{\text{ - }}{\text{ + Y}}{{\text{C}}_{\text{2}}}{\text{O}}_{\text{4}}^{{\text{2 - }}} \rightleftharpoons {\text{XM}}{{\text{n}}^{{\text{2 + }}}}{\text{ + YC}}{{\text{O}}_{\text{2}}}{\text{ + }}\frac{{\text{Z}}}{{\text{2}}}{{\text{H}}_{\text{2}}}{\text{O}}}\)
values of X, Y and Z respectively are

1 2, 5, 16
2 8, 2, 5
3 5, 2, 16
4 5, 8, 4
CHXI08:REDOX REACTIONS

315086 Reaction of liquid hydrazine \(\mathrm{\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)}\) with chlorate ion \(\mathrm{\left(\mathrm{ClO}_{3}^{-}\right)}\)in basic medium produces nitric oxide gas and chloride ion in gaseous state. The balanced chemical equation for the reaction is

1 \(\mathrm{\mathrm{N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow \mathrm{NO}+3 \mathrm{Cl}^{-}+\mathrm{H}_{2} \mathrm{O}}\)
2 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+4 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
3 \(\mathrm{3 \mathrm{~N}_{2} \mathrm{H}_{4}+3 \mathrm{ClO}_{3}^{-} \rightarrow 6 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)
4 \(\mathrm{4 \mathrm{~N}_{2} \mathrm{H}_{4}+4 \mathrm{ClO}_{3}^{-} \rightarrow 8 \mathrm{NO}+3 \mathrm{Cl}^{-}+6 \mathrm{H}_{2} \mathrm{O}}\)