Download App

Redox Reactions — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryRedox Reactions3 Marks
Question
Balance the following ionic equations.
$\text{MnO}^-_4+\text{H}^++\text{Br}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Mn}^{2+}+\text{Br}_2+\text{H}_2\text{O}$
✓

Answer


Dividing the equation into two half reactions:
Oxidation half reaction: $\text{Br}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Br}_2$
Reduction half reaction: $\text{MnO}^-_4\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Mn}^{2+}$
Balancing oxidation and reduction half reactions separately as:
Oxidation half reaction
$\text{Br}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Br}_2$
$2\text{Br}^-\xrightarrow{ \ \ \ \ \ \ \ \ \ }\text{Br}_2$
$2\text{Br}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Br}_2+2\text{e}^-...(\text{i})$
Reduction half reaction
$\text{MnO}^-_4\xrightarrow{ \ \ \ \ \ \ \ }\text{Mn}^{2+}$
$\text{MnO}^-_4+5\text{e}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Mn}^{2+}$
$\text{MnO}^-_4+8\text{H}^++5\text{e}^-\xrightarrow{ \ \ \ \ \ \ \ }\text{Mn}^{2+}$
$\text{MnO}^-_4+8\text{H}^++5\text{e}^-\xrightarrow{ \ \ \ \ \ \ \ \ }\text{Mn}^{2+}+4\text{H}_2\text{O}...(\text{ii})$
To balance the electrons, multiply eq. (i) by 5 and eq. (ii) by 2 and add
$2\text{MnO}^-_4+10\text{Br}^-+16\text{H}^+\xrightarrow{ \ \ \ \ \ \ \ \ }2\text{Mn}^{2+}+5\text{Br}_2+8\text{H}_2\text{O}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Redox Reactions→Redox Reactions — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

What is meant by entropy? Predict the sign of entropy change in each of the following:
  1. H2 (at 298K, 1atm) → H2 (at 298K, 10atm)
  2. H2O (at 298K, 1atm) → H­2O (at 330K, 1atm)
  3. 2NH4NO3(s) → 2N2(g) + 4H2O(g) + O2(8)
  4. Crystallization of copper sulphate from its saturated solution.
  5. $2\text{SO}_2(\text{g})+\text{O}_2(\text{g})\rightleftharpoons2\text{SO}_3(\text{g}).$
→
Which of the following compounds are aromatic according to Huckel's rule?

→
In a hydrogen atom, the energy of an electron in first Bohr's orbit is $E _{ n }=-\frac{2 \pi^2 me ^4}{ n ^2 h^2}$.
What is the energy required for its excitation to Bohr's second orbit?
→
How do atomic radius vary in a period and in a group? How do you explain the variation?
→
For the reaction,
2Cl(g) → Cl2(g), what are the signs of $\Delta\text{H}$ and $\Delta\text{S}?$
→
Which of the two: O2NCH2CH2O- or CH3CH2O- is expected to be more stable and why?
→
An ion with mass number 37 possesses one unit of negative charge. If the ion conatins 11.1% more neutrons than the electrons, find the symbol of the ion.
→
For the following bond cleavages, use curved-arrows to show the electron flow and classify each as homolysis or heterolysis. Identify reactive intermediate produced as free radical, carbocation and carbanion.

→
If ice and water are in equilibrium at $0^{\circ} C$ then $\Delta H =6.0 kJ mol ^{-1}$. Find value of $\Delta S$ and $\Delta G$.
→
Calculate the molarity of a solution of ethanol in water, in which the mole fraction of ethanol is 0.040 (assume the density of water to be one).
→