Question

question 4 (1 point)
how many hydrogen ions must be added to the half reaction given below to balance the mass for hydrogen atoms?
mno₄⁻(aq) → mno₂(s)

a) 1 on the left side

b) 2 on the right side

c) 4 on the right side

d) 2 on the left side

e) 4 on the left side

Explanation:

Step1: Balance oxygen atoms

To balance oxygen, we add water molecules. The left side has 4 O atoms (\(MnO_4^-\)) and the right side has 2 O atoms (\(MnO_2\)). So we add 2 \(H_2O\) to the right side:
\(MnO_4^-(aq)
ightarrow MnO_2(s) + 2H_2O(l)\)

Step2: Balance hydrogen atoms

Now, the right side has 4 H atoms (from \(2H_2O\)). To balance H, we add \(H^+\) (hydrogen ions) to the left side. Since there are 4 H atoms on the right, we add 4 \(H^+\) to the left:
\(4H^+(aq) + MnO_4^-(aq)
ightarrow MnO_2(s) + 2H_2O(l)\)

Answer:

e) 4 on the left side