I need the oxidation half reactions, reduction half reactions, and net ionic equations for the following reactions:
1)magnesium +0.1M zinc sulfate
2)copper+0.1M zinc sulfate
3)zinc+0.1M copper(II)sulfate
4)zinc+3M HCl
5)copper+3M HCl
6)0.1M potassium iodide+ 0.1M copper(II)sulfate
7)0.1M potassium iodide + 0.02M potassium iodate
8)0.1M potassium iodide+ 0.1M potassium ferricyanide
9)0.1M iron(III) chloride + 0.1M potassium iodide
10)0.1M iron(III)chloride +0.1M potassium bromide
11)3% hydrogen peroxide + 0.1M cerium(IV)ammonium nitrate
12)aqueous iodine + 1M sodium thiosulfate
Here is the way you do #1.
Mg(s) + ZnSO4(aq) ==> MgSO4(aq) + Zn(s)
1. How do you know Mg will displace Zn? Look at the activity series. A metal will displace any ion below it. Mg is above Zn; therefore, it will displace Zn^+2. Here is a chart.
http://www.files.chem.vt.edu/RVGS/ACT/notes/activity_series.html
half reactions:
You pick them out. Mg goes to Mg^+2 and Zn^+2 goes to Zn.
Mg ==> Mg^+2 + 2e is oxidation (loss of electrons)
Zn^+2 + 2e ==> Zn is reduction (gain of electrons).
Add the two to obtain the net ionic equation.
Mg(s) + Zn^+2(aq) --> Mg^+2(aq) + Zn(s)
#12.
I2(aq) + 2Na2S2O3 ==> 2I^- + 4Na^+ = S4O6^-2
I2 + 2e ==> 2I^- reduction
2S2O3^-2 ==> S4O6^-2 + 2e oxidation
net ionic:
I2(aq) + 2S2O3^-2(aq) ==> 2I^-(aq) + S4O6^-2(aq)
Mg(s) + ZnSO4(aq) ==> MgSO4(aq) + Zn(s)
1. How do you know Mg will displace Zn? Look at the activity series. A metal will displace any ion below it. Mg is above Zn; therefore, it will displace Zn^+2. Here is a chart.
Sure, I can help you with that. Here are the oxidation half reactions, reduction half reactions, and net ionic equations for the given reactions:
1) Magnesium + 0.1M Zinc Sulfate
Oxidation Half Reaction: Mg -> Mg2+ + 2e^-
Reduction Half Reaction: Zn2+ + 2e^- -> Zn
Net Ionic Equation: Mg + Zn2+ -> Mg2+ + Zn
2) Copper + 0.1M Zinc Sulfate
Oxidation Half Reaction: Cu -> Cu2+ + 2e^-
Reduction Half Reaction: Zn2+ + 2e^- -> Zn
Net Ionic Equation: Cu + Zn2+ -> Cu2+ + Zn
3) Zinc + 0.1M Copper(II) Sulfate
Oxidation Half Reaction: Zn -> Zn2+ + 2e^-
Reduction Half Reaction: Cu2+ + 2e^- -> Cu
Net Ionic Equation: Zn + Cu2+ -> Zn2+ + Cu
4) Zinc + 3M HCl
Oxidation Half Reaction: Zn -> Zn2+ + 2e^-
Reduction Half Reaction: 2H+ + 2e^- -> H2
Net Ionic Equation: Zn + 2H+ -> Zn2+ + H2
5) Copper + 3M HCl
Oxidation Half Reaction: Cu -> Cu2+ + 2e^-
Reduction Half Reaction: 2H+ + 2e^- -> H2
Net Ionic Equation: Cu + 2H+ -> Cu2+ + H2
6) 0.1M Potassium Iodide + 0.1M Copper(II) Sulfate
Oxidation Half Reaction: I^- -> I2 + 2e^-
Reduction Half Reaction: Cu2+ + 2e^- -> Cu
Net Ionic Equation: 2I^- + Cu2+ -> I2 + Cu
7) 0.1M Potassium Iodide + 0.02M Potassium Iodate
Oxidation Half Reaction: I^- -> I2 + 2e^-
Reduction Half Reaction: IO3^- + 6H+ + 6e^- -> 3H2O + I^-
Net Ionic Equation: 2IO3^- + 12H+ + 10I^- -> 5I2 + 6H2O
8) 0.1M Potassium Iodide + 0.1M Potassium Ferricyanide
Oxidation Half Reaction: I^- -> I2 + 2e^-
Reduction Half Reaction: [Fe(CN)6]3- + e^- -> [Fe(CN)6]4-
Net Ionic Equation: 2I^- + [Fe(CN)6]3- -> I2 + [Fe(CN)6]4-
9) 0.1M Iron(III) Chloride + 0.1M Potassium Iodide
Oxidation Half Reaction: I^- -> I2 + 2e^-
Reduction Half Reaction: Fe3+ + 3e^- -> Fe
Net Ionic Equation: 2I^- + 2Fe3+ -> I2 + 2Fe
10) 0.1M Iron(III) Chloride + 0.1M Potassium Bromide
Oxidation Half Reaction: Br^- -> Br2 + 2e^-
Reduction Half Reaction: Fe3+ + 3e^- -> Fe
Net Ionic Equation: 6Br^- + 2Fe3+ -> 3Br2 + 2Fe
11) 3% Hydrogen Peroxide + 0.1M Cerium(IV) Ammonium Nitrate
Oxidation Half Reaction: H2O2 -> O2 + 2H+ + 2e^-
Reduction Half Reaction: Ce4+ + e^- -> Ce3+
Net Ionic Equation: H2O2 + Ce4+ -> O2 + 2H+ + Ce3+
12) Aqueous Iodine + 1M Sodium Thiosulfate
Oxidation Half Reaction: I2 + 2e^- -> 2I^-
Reduction Half Reaction: 2S2O3^2- -> S4O6^2- + 2e^-
Net Ionic Equation: I2 + 2S2O3^2- -> 2I^- + S4O6^2-
To determine the oxidation half reactions, reduction half reactions, and net ionic equations for the given reactions, we need to identify the compounds undergoing oxidation and reduction and balance the equations.
1) Magnesium + 0.1M Zinc Sulfate:
The reaction can be represented as:
Mg(s) + ZnSO4(aq) -> Zn(s) + MgSO4(aq)
Oxidation Half Reaction:
Mg(s) -> Mg^2+(aq) + 2e^-
Reduction Half Reaction:
Zn^2+(aq) + 2e^- -> Zn(s)
Net Ionic Equation:
Mg(s) + Zn^2+(aq) -> Zn(s) + Mg^2+(aq)
2) Copper + 0.1M Zinc Sulfate:
The reaction can be represented as:
Cu(s) + ZnSO4(aq) -> Zn(s) + CuSO4(aq)
Oxidation Half Reaction:
No oxidation occurs. Copper remains unchanged.
Reduction Half Reaction:
Zn^2+(aq) + 2e^- -> Zn(s)
Net Ionic Equation:
Cu(s) + Zn^2+(aq) -> Zn(s) + CuSO4(aq)
3) Zinc + 0.1M Copper(II) Sulfate:
The reaction can be represented as:
Zn(s) + CuSO4(aq) -> Cu(s) + ZnSO4(aq)
Oxidation Half Reaction:
No oxidation occurs. Zinc remains unchanged.
Reduction Half Reaction:
Cu^2+(aq) + 2e^- -> Cu(s)
Net Ionic Equation:
Zn(s) + Cu^2+(aq) -> Cu(s) + ZnSO4(aq)
4) Zinc + 3M HCl:
The reaction can be represented as:
Zn(s) + 2HCl(aq) -> ZnCl2(aq) + H2(g)
Oxidation Half Reaction:
No oxidation occurs. Zinc remains unchanged.
Reduction Half Reaction:
2H^+(aq) + 2e^- -> H2(g)
Net Ionic Equation:
Zn(s) + 2H^+(aq) -> ZnCl2(aq) + H2(g)
5) Copper + 3M HCl:
The reaction can be represented as:
Cu(s) + 2HCl(aq) -> CuCl2(aq) + H2(g)
Oxidation Half Reaction:
No oxidation occurs. Copper remains unchanged.
Reduction Half Reaction:
2H^+(aq) + 2e^- -> H2(g)
Net Ionic Equation:
Cu(s) + 2H^+(aq) -> CuCl2(aq) + H2(g)
6) 0.1M Potassium Iodide + 0.1M Copper(II) Sulfate:
The reaction can be represented as:
2KI(aq) + CuSO4(aq) -> CuI2(aq) + K2SO4(aq)
Oxidation Half Reaction:
No oxidation occurs. Iodide ions remain unchanged.
Reduction Half Reaction:
Cu^2+(aq) + 2e^- -> Cu(s)
Net Ionic Equation:
2I^-(aq) + Cu^2+(aq) -> CuI2(aq)
The same approach can be used to find the half reactions and net ionic equations for the remaining reactions (7-12).