Advertisements
Advertisements
प्रश्न
Balance the following redox equation by half-reaction method.
\[\ce{H2C2O_{4(aq)} + MnO^-_{4(aq)}->CO2_{(g)} + Mn^2+_{( aq)}(acidic)}\]
Advertisements
उत्तर
\[\ce{H2C2O_{4(aq)} + MnO^-_{4(aq)}->CO2_{(g)} + Mn^2+_{( aq)}}\]
Step 1: Write the unbalanced equation for the redox reaction. Assign the oxidation number to all the atoms in reactants and products. Divide the equation into two half equations.

- Oxidation half-reaction: \[\ce{H2C2O_{4(aq)}->CO2_{(g)}}\]
- Reduction half-reaction: \[\ce{MnO^-_{4(aq)}->Mn^2+_{( aq)}}\]
Step 2: Balance the atoms except O and H in each half equation. Balance half equation for O atoms by adding 4H2O to the right side of the reduction half equation.
- Oxidation: \[\ce{H2C2O_{4(aq)}->2CO2_{(g)}}\]
- Reduction: \[\ce{MnO^-_{4(aq)}->Mn^2+_{( aq)} + 4H2O_{(l)}}\]
Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence, add 2H+ ions to the right side of the oxidation half equation and 8H+ ions to the left side of the reduction half equation.
- Oxidation: \[\ce{H2C2O_{4(aq)}->2CO2_{(g)} + 2H^+_{( aq)}}\]
- Reduction: \[\ce{MnO^-_{4(aq)} + 8H^+_{( aq)}->Mn^2+_{( aq)} + 4H2O_{(l)}}\]
Step 4: Now add 2 electrons to the right side of the oxidation half equation and 5 electrons to the left side of the reduction half equation to balance the charges.
- Oxidation: \[\ce{H2C2O_{4(aq)}->2CO2_{(g)} + 2H^+_{( aq)} + 2e^-}\]
- Reduction: \[\ce{MnO^-_{4(aq)} + 8H^+_{( aq)} + 5e^-->Mn^2+_{( aq)} + 4H2O_{(l)}}\]
Step 5: Multiply oxidation half equation by 5 and reduction half equation by 2 to equalize the number of electrons in two half equations. Then add two half equations.
- Oxidation: \[\ce{5H2C2O_{4(aq)}->10CO2_{(g)} + 10H^+_{( aq)} + 10e^-}\]
- Reduction: \[\ce{2MnO^-_{4(aq)} + 16H^+_{( aq)} + 10e^-->2Mn^2+_{( aq)} + 8H2O_{(l)}}\]
Add two half equations:
\[\ce{5H2C2O_{4(aq)} + 2MnO^-_{4(aq)} + 6H^+_{( aq)}->10CO2 + 2Mn^2+_{( aq)} + 8H2O_{(l)}}\]
The equation is balanced in terms of the number of atoms and the charges.
Hence, balanced equation: \[\ce{5H2C2O_{4(aq)} + 2MnO^-_{4(aq)} + 6H^+_{( aq)}->10CO2 + 2Mn^2+_{( aq)} + 8H2O_{(l)}}\]
APPEARS IN
संबंधित प्रश्न
Whenever a reaction between an oxidising agent and a reducing agent is carried out, a compound of lower oxidation state is formed if the reducing agent is in excess and a compound of higher oxidation state is formed if the oxidising agent is in excess. Justify this statement giving three illustrations.
Balance the following redox reactions by ion-electron method:
- \[\ce{MnO-_4 (aq) + I– (aq) → MnO2 (s) + I2(s) (in basic medium)}\]
- \[\ce{MnO-_4 (aq) + SO2 (g) → Mn^{2+} (aq) + HSO-_4 (aq) (in acidic solution)}\]
- \[\ce{H2O2 (aq) + Fe^{2+} (aq) → Fe^{3+} (aq) + H2O (l) (in acidic solution)}\]
- \[\ce{Cr_2O^{2-}_7 + SO2(g) → Cr^{3+} (aq) + SO^{2-}_4 (aq) (in acidic solution)}\]
Balance the following equation in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
\[\ce{Cl_2O_{7(g)} + H_2O_{2(aq)} -> ClO-_{2(aq)} + O_{2(g)} + H+_{(aq)}}\]
The Mn3+ ion is unstable in solution and undergoes disproportionation to give Mn2+, MnO2, and H+ ion. Write a balanced ionic equation for the reaction.
Chlorine is used to purify drinking water. Excess of chlorine is harmful. The excess of chlorine is removed by treating with sulphur dioxide. Present a balanced equation for this redox change taking place in water.
Choose the correct option.
For the following redox reactions, find the correct statement.
\[\ce{Sn^{2⊕} + 2Fe^{3⊕}->Sn^{4⊕} + 2Fe^{2⊕}}\]
Balance the following reaction by oxidation number method.
\[\ce{Cr2O^2-_{7(aq)} + SO^2-_{3(aq)}->Cr^3+_{ (aq)} + SO^2-_{4(aq)}(acidic)}\]
Which of the following is INCORRECT for the following reaction?
\[\ce{2Zn_{(s)} + O2_{(g)} -> 2ZnO_{(s)}}\]
Which of the following is a redox reaction?
When methane is burnt completely, oxidation state of carbon changes from ______.
Write balanced chemical equation for the following reactions:
Reaction of liquid hydrazine \[\ce{(N2H4)}\] with chlorate ion \[\ce{(ClO^{-}3)}\] in basic medium produces nitric oxide gas and chloride ion in gaseous state.
Write balanced chemical equation for the following reactions:
Dichlorine heptaoxide \[\ce{(Cl2O7)}\] in gaseous state combines with an aqueous solution of hydrogen peroxide in acidic medium to give chlorite ion \[\ce{(ClO^{-}2)}\] and oxygen gas. (Balance by ion-electron method)
Balance the following equations by the oxidation number method.
\[\ce{I2 + NO^{-}3 -> NO2 + IO^{-}3}\]
Balance the following equations by the oxidation number method.
\[\ce{I2 + S2O^{2-}3 -> I- + S4O^{2-}6}\]
Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.
\[\ce{HgCl2 (aq) + 2KI (aq) -> HgI2 (s) + 2KCl (aq)}\]
Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.
\[\ce{PCl3 (l) + 3H2O (l) -> 3HCl (aq) + H3PO3 (aq)}\]
Identify the redox reactions out of the following reactions and identify the oxidising and reducing agents in them.
\[\ce{4NH3 (g) + 3O2 (g) -> 2N2 (g) + 6H2O (g)}\]
Balance the following ionic equations.
\[\ce{Cr2O^{2-}7 + Fe^{2+} + H+ -> Cr^{3+} + Fe^{3+} + H2O}\]
Balance the following ionic equations.
\[\ce{MnO^{-}4 + SO^{2-}3 + H^{+} -> Mn^{2+} + SO^{2-}4 + H2O}\]
Balance the following ionic equations.
\[\ce{MnO^{-}4 + H^{+} + Br^{-} -> Mn^{2+} + Br2 + H2O}\]
The weight of CO is required to form Re2(CO)10 will be ______ g, from 2.50 g of Re2O7 according to given reaction
\[\ce{Re2O7 + CO -> Re2(CO)10 + CO2}\]
Atomic weight of Re = 186.2; C = 12 and O = 16.
In the reaction of oxalate with permanganate in an acidic medium, the number of electrons involved in producing one molecule of CO2 is ______.
Consider the following reaction:
\[\ce{xMnO^-_4 + yC2O^{2-}_4 + zH^+ -> xMn^{2+} + 2{y}CO2 + z/2H2O}\]
The values of x, y, and z in the reaction are, respectively:
