Balancing Redox Reactions: Acidic Solutions Video Lessons

Concept: Balancing Redox Reactions: Acidic Solutions

# Problem: Balance the following equation in acidic conditions. Phases are optional. Cr2 + H2MoO4 ::&gt; Cr3  + Mo

###### FREE Expert Solution

Balance the redox reaction under acidic conditions:

Cr2+(aq)  + H2MoO4(aq) → Cr3+(aq) + Mo(s)

*Before balancing the redox reaction:

ignore H+, OH-, and H2O in the starting reaction

Step 1: Separate the whole reaction into two half-reactions

Cr2+(aq)  →  Cr3+(aq)                                                    H2MoO4(aq)Mo(s)

Step 2: Balance the non-hydrogen and non-oxygen elements first

Cr2+(aq)  →  Cr3+(aq)                                                    H2MoO4(aq)Mo(s)

(Cr: balanced)                                               (Mo: balanced)

Step 3: Balance oxygen by adding H2O(l) to the side that needs oxygen (1 O : 1 H2O)

Cr2+(aq)  →  Cr3+(aq)                                                    H2MoO4(aq)Mo(s) + 4H2O(l)

(No oxygens)

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###### Problem Details

Balance the following equation in acidic conditions. Phases are optional.

Cr2 + H2MoO4 ::> Cr3  + Mo