Balance the reaction between MnO2 and Cd to form Mn^{2+} and Cd^{2+} in acidic solution. When you...


Balance the reaction between MnO2 and Cd to form Mn{eq}^{2+} {/eq} and Cd{eq}^{2+} {/eq} in acidic solution. When you have balanced the equation using the smallest integers possible, enter the coefficients of the species shown.

_____MnO2 + _____Cd {eq}\rightarrow {/eq} _____ Mn{eq}^{2+} {/eq} + _____ Cd{eq}^{2+} {/eq}

Water appears in the balanced equation as a _____ (reactant, product, neither) with a coefficient of _____. (Enter 0 for neither.)

How many electrons are transferred in this reaction? _____

Redox Reactions:

A redox reaction would be more complicated to balance. We consider the reaction if it occurs in an acidic or alkaline solutions. For instance, when the reaction occurs in acidic solutions, we would have to add {eq}\displaystyle H_2O {/eq} to provide O atoms and {eq}\displaystyle H^+ {/eq} to provide H atoms. Also, if necessary, we need to add electrons if charges are not balanced.

Answer and Explanation: 1

Balance the given reaction in acidic solution. We do this by first individually balancing the resepective Mn and Cd atoms in the equation. Afterwards, we add {eq}\displaystyle H_2O {/eq} for the side that lacks O atoms, and {eq}\displaystyle H^+ {/eq} for the side that lacks H atoms. Finally, we add electrons to balance charges. We proceed with the solution.

{eq}\begin{align} \displaystyle MnO_2+Cd &\to Mn^{2+} +Cd^{2+}\\ \text{Balance O.}\\ MnO_2+Cd &\to Mn^{2+} +Cd^{2+}+ 2H_2O\\ \text{Balance H.}\\ MnO_2+Cd + 4H^{+} &\to Mn^{2+} +Cd^{2+}+ 2H_2O\\ \end{align} {/eq}

Therefore, water appears in the balanced equation as a product with a coefficient of 2 and there are 0 electrons transferred.

Learn more about this topic:

Redox Reactions & Electron Carriers in Cellular Respiration: Definitions and Examples


Chapter 8 / Lesson 4

Learn what electron carriers are in cellular respiration. Study the main redox reactions and identify what oxidized and reduced mean in cellular respiration.

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