Determine whether the following are redox reactions. If a redox rxn., identify the oxidized reactant and the reduced reactant.
a)N2 + 3H2-->2NH3 : YES, Oxidized=H, Reduced: N
b)2H2O2-->2H2O + O2 : YES, Oxidized=H, Reduced: O
c)2HBr + Ca(OH)2 -->CaBr2 + 2H20 : N0
d)2Fe + 6HCl -->2FeCl3 + 3H2 : YES, Oxidized: Fe, Reduced: H
e) 2NaHCO3 -->Na2CO3 + H2O + CO2 : NO
all correct.
a) YES, Oxidized=H, Reduced: N
b) YES, Oxidized=H, Reduced: O
c) NO
d) YES, Oxidized: Fe, Reduced: H
e) NO
To determine whether a reaction is a redox reaction, you need to compare the oxidation states of the elements before and after the reaction.
a) N2 + 3H2 --> 2NH3: This is a redox reaction because nitrogen (N) is reduced from an oxidation state of 0 to -3 in NH3, while hydrogen (H) is oxidized from an oxidation state of 0 to +1 in NH3. Oxidized reactant: H2, Reduced reactant: N2.
b) 2H2O2 --> 2H2O + O2: This is a redox reaction because hydrogen (H) is reduced from an oxidation state of +1 in H2O2 to 0 in H2O, and oxygen (O) is oxidized from an oxidation state of -1 in H2O2 to 0 in O2. Oxidized reactant: H2O2, Reduced reactant: O2.
c) 2HBr + Ca(OH)2 --> CaBr2 + 2H2O: This is not a redox reaction because there is no change in oxidation states for any of the elements involved. The oxidation state of hydrogen remains +1 in both HBr and H2O, the oxidation state of bromine remains -1 in both HBr and CaBr2, and the oxidation state of calcium remains +2 in Ca(OH)2 and CaBr2.
d) 2Fe + 6HCl --> 2FeCl3 + 3H2: This is a redox reaction because iron (Fe) is oxidized from an oxidation state of 0 to +3 in FeCl3, and hydrogen (H) is reduced from an oxidation state of +1 in HCl to 0 in H2. Oxidized reactant: Fe, Reduced reactant: HCl.
e) 2NaHCO3 --> Na2CO3 + H2O + CO2: This is not a redox reaction because there is no change in oxidation states for any of the elements involved. The oxidation state of sodium remains +1 in both NaHCO3 and Na2CO3, the oxidation state of hydrogen remains +1 in both NaHCO3 and H2O, and the oxidation state of carbon remains +4 in both NaHCO3 and CO2.