Answer:
2CO 2NO → 2CO2 N2 : Balanced
6CO2 6H2O → C6H12O6 : Unbalanced
H2CO3 → H2O CO2 : Balanced
2Cu O2 → CuO : Unbalanced
Explanation:
1.) 2CO 2NO → 2CO2 N2
2 Carbon 2
4 Oxygen 4
2 Nitrogen 2
The amount of atoms of each element on each side of the equation are the same therefore the equation is balanced.
2.) 6CO2 6H2O → C6H12O6 O2
6 Carbon 6
12 Oxygen 8
12 Hydrogen 12
The amount of oxygen atoms is different on both sides of the equation therefore the equation is not balanced.
3.) H2CO3 → H2O CO2
2 Hydrogen 2
1 Carbon 1
3 Oxygen 3
The amount of atoms of each element is the same on both sides of the equation therefore the equation is balanced.
2Cu O2 → CuO.
2 Cu 2
2 O 1
The amount of oxygen atoms is different on both sides of the equation therefore the equation is not balanced.
After finding the oxidation states of atoms, you identify the half reactions (option c).
The half reactions are given by the change of the oxidation states of the atoms.
For example if Cu is in the left side with oxidation state 0 and in the other side with oxidation state 2+, then there you have a half reaction (oxidation reaction). And if you have O with oxidation state 0 in the left side and with oxidation state 2- in the right side, there you have other half reaction (reducing reaction).
