Identify any elements that changed oxidation number in the reactions in the model. Connect the starting and ending oxidation numbers with a line. An example is shown. 4Fe(s) 2Fe20 3026) 0 0 0 +3-2 +3-2 -2 12. Based on the oxidation number analysis you just performed, are there any features of the redox reactions that would allow you to identify them? Use specific examples to support your answer. 13. Identify the following reactions as either redox or non-redox using oxidation numbers as evidence. – a. Pb(NO3)2(aq) + 2Nal(a) ? Pb12() + 2NaNO3(av) – b.2H206+2H20) + 026) C. CH4) +2020) + 2H20) + CO26) + – d. HCl(aq) + NaOH(aq) ? H200 + NaCl(aq)
The Correct Answer and Explanation is :
n redox reactions, elements undergo changes in their oxidation numbers, indicating the transfer of electrons.y analyzing these changes, we can identify which elements are oxidized and which are reduced.
11. Identifying Changes in Oxidation Numbers:
onsider the reaction:
[ 4\text{Fe}(s) + 3\text{O}_2(g) \rightarrow 2\text{Fe}_2\text{O}_3(s) ]
Assigning oxidation numbers:
- e in its elemental form (Fe) has an oxidation number of 0.- xygen in its elemental form (O₂) also has an oxidation number of 0.- n Fe₂O₃, iron has an oxidation number of +3, and oxygen has an oxidation number of -2.
onnecting the changes: - e: 0 → +3 (oxidation)- : 0 → -2 (reduction)
his indicates that iron is oxidized, and oxygen is reduced.
12. Features of Redox Reactions:
edox reactions are characterized by the change in oxidation numbers of the involved elements.pecifically:
- Oxidation: n increase in oxidation number due to the loss of electrons.- Reduction: decrease in oxidation number due to the gain of electrons.
or example, in the reaction between zinc and copper(II) ions:
[ \text{Zn}(s) + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s) ]
ssigning oxidation numbers: - n: 0 → +2 (oxidation)- u: +2 → 0 (reduction)
ere, zinc is oxidized (loses electrons), and copper is reduced (gains electrons).he simultaneous occurrence of oxidation and reduction, with corresponding changes in oxidation numbers, is a key feature of redox reactions.
13. Classifying Reactions as Redox or Non-Redox:
o determine if a reaction is redox, analyze the oxidation numbers of all elements before and after the reaction. change in oxidation numbers indicates a redox reaction.
a. [ \text{Pb(NO}_3\text{)}_2(aq) + 2\text{NaI}(aq) \rightarrow \text{PbI}_2(s) + 2\text{NaNO}_3(aq) ]
Assigning oxidation numbers:
- b: +2 (in both reactants and products)- : +5 (in both reactants and products)- : -2 (in both reactants and products)- a: +1 (in both reactants and products)- : -1 (in both reactants and products)
ince there is no change in oxidation numbers, this is a non-redox reaction.
b. [ 2\text{H}_2\text{O}_2(aq) \rightarrow 2\text{H}_2\text{O}(l) + \text{O}_2(g) ]
Assigning oxidation numbers: - : +1 (in both reactants and products)- in H₂O₂: -1- in H₂O: -2- in O₂: 0
xygen undergoes both oxidation (-1 to 0) and reduction (-1 to -2), indicating a redox reaction.
c. [ \text{CH}_4(g) + 2\text{O}_2(g) \rightarrow \text{CO}_2(g) + 2\text{H}_2\text{O}(l) ]
Assigning oxidation numbers: - in CH₄: -4- : +1- in O₂: 0- in CO₂: +4- in CO₂ and H₂O: -2
arbon is oxidized (-4 to +4), and oxygen is reduced (0 to -2), indicating a redox reaction.
d. [ \text{HCl}(aq) + \text{NaOH}(aq) \rightarrow \text{H}_2\text{O}(l) + \text{NaCl}(aq) ]
Assigning oxidation numbers: - : +1 (in both reactants and products)- l: -1 (in both reactants and products)- a: +1 (in both reactants and products)- : -2 (in both reactants and products)
ince there is no change in oxidation numbers, this is a non-redox reaction.
n summary, redox reactions are characterized by changes in oxidation numbers, reflecting the transfer of electrons between species.y analyzing these changes, we can identify which reactions involve oxidation-reduction processes and which do not.