In: Chemistry
number of electrons transferred = 24
Explanation
The balanced reaction is : 3 CuS (s) + 8 HNO3 (aq) 3 CuSO4 (aq) + 8 NO (g) + 4 H2O (l)
We have to check the oxidation number of each element before and after reaction
Before reaction | ||
Compound | element | oxidation number |
CuS | Cu | +2 |
S | -2 | |
HNO3 | H | +1 |
N | +5 | |
O | -2 | |
After reaction | ||
Compound | element | oxidation number |
CuSO4 | Cu | +2 |
S | +6 | |
O | -2 | |
NO | N | +2 |
O | -2 | |
H2O | H | -1 |
O | +2 |
From the table, we see that oxidation number of sulfur changes from -2 to +6
This means each sulfur atom loses 8 electrons.
Since there are 3 sulfur atom in the balanced equation, therefore, total atoms lost by sulfur = 3 * 8 = 24 electrons