Answer:
Assign an oxidation state to each element in each reaction and use the change in oxidation state to determine which element is being oxidized and which element is being reduced.
1. C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g)
2. C2H4(g)+Cl2(g)→C2H4Cl2(g)
Step-by-step explanation:
1- In the reaction, C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g), the oxidation state of each element changes as follows:
C6H12O6: C: -1 to +4; H: +1 to +1; O: -2 to -2
O2: O: 0 to -2
CO2: C: +4 to +4; O: -2 to -2
H2O: H: +1 to +1; O: -2 to -2
2- In this reaction, oxygen (O2) is being reduced, since its oxidation state changes from 0 to -2. Carbon (C6H12O6) is being oxidized, since its oxidation state changes from -1 to +4.
In the reaction, C2H4(g)+Cl2(g)→C2H4Cl2(g), the oxidation state of each element changes as follows:
C2H4: C: -3 to -2; H: +1 to +1
Cl2: Cl: 0 to 0
C2H4Cl2: C: -2 to -2; H: +1 to +1; Cl: 0 to -1
In this reaction, chlorine (Cl2) is being reduced, since its oxidation state changes from 0 to -1. Ethene (C2H4) is being oxidized, since its oxidation state changes from -3 to -2.