Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of Pb and H + in the balanced reaction?
Pb 2+ (aq)+ NH 4 + (aq)? Pb(s)+ NO 3 ?(aq)
A) Pb = 1, H? = 8
B) Pb = 1, H? = 2
C) Pb = 4, H? = 10
D) Pb = 2, H? = 3
E) Pb = 3, H? = 5

Question

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of Pb and H + in the balanced reaction? 
Pb 2+ (aq)+ NH 4 + (aq)? Pb(s)+ NO 3 ?(aq)
A) Pb = 1, H? = 8
B) Pb = 1, H? = 2
C) Pb = 4, H? = 10
D) Pb = 2, H? = 3
E) Pb = 3, H? = 5

Quizplus · Accepted Answer

The balanced equation is: 
PbS1U1P12 + 8HS1U1B14S1U1B0 + 5NOS1U1B13S1U1B0⁻ → Pb + 5NOS1U1B13S1U1B0⁻ + 4HS1U1P1 + S1S1P0 
To balance the equation, the first step is to assign oxidation states: 
Pb in PbS1U1P12 → Pb in Pb: 0 (elemental form) 
S in PbS1U1P12 → S in S1U1B0: -2 
P in PbS1U1P12 → P in S1U1P1: +5 
S in S1S1P0 → S in S1U1B0: -2 
P in S1S1P0 → P in S1U1P1: +5 
N in NOS1U1B13S1U1B0⁻ → N in NO: +2 
S in NOS1U1B13S1U1B0⁻ → S in S1U1B0: -2 
B in NHS1U1B14S1U1B0 → B in S1U1B0⁻: +3 
H in NHS1U1B14S1U1B0 → H in HS1U1P1: +1 
Next, balance the number of atoms of each element, starting with elements that occur only once on each side of the equation: 
PbS1U1P12 + 8HS1U1B14S1U1B0 + 5NOS1U1B13S1U1B0⁻ → Pb + 5NOS1U1B13S1U1B0⁻ + 4HS1U1P1 + S1S1P0 
1 Pb: 1 Pb 
2 P: 1 PbS1U1P12, 1S1U1P1 
2 P: 1S1S1P0, 5NOS1U1B13S1U1B0⁻ 
10 H: 8HS1U1B14S1U1B0, 4HS1U1P1 
4 S: 1 PbS1U1P12, 1S1S1P0, 5NOS1U1B13S1U1B0⁻, 8HS1U1B14S1U1B0, 1S1U1B0⁻ 
Finally, balance the charges by adding electrons: 
PbS1U1P12 + 8HS1U1B14S1U1B0 + 5NOS1U1B13S1U1B0⁻ → Pb + 5NOS1U1B13S1U1B0⁻ + 4HS1U1P1 + S1S1P0 + 12e- 
Balance the half-reactions: 
Oxidation: PbS1U1P12 → Pb + 2e- (multiply by 2) 
Reduction: 8H⁺ + 5NO3⁻ + 12e- → 5NO + 4H2O (multiply by 3) 
The final balanced equation is: 
2PbS1U1P12 + 16HS1U1B14S1U1B0 + 15NOS1U1B13S1U1B0⁻ → 2Pb + 25NO + 8HS1U1P1 + 2S1S1P0 + 16H2O 
Therefore, the coefficients in front of Pb, S1U1B0⁻, and HS1U1P1 are Pb = 4, S1U1B0⁻ = 10, and HS1U1P1 = 8. The best choice is C.

Balance the Following Redox Reaction If It Occurs in Acidic