Question

Скласти рівняння окисно-відновних реакцій. Позначте окисник і відновник. 1. Mg + N2 - Mg3N2 2. KMnO4 - R2MnO4 + MnO2 + O2 3. Ag + O2 - Ag2O 4. Ag +O2 - K2MnO4 + MnO2 + O2 5. Cr + Cl2 - CrCl3 6. H2S + Cl2 - S + HCl

Answer 1

1. 6Mg⁰ + 3N₂⁰ = 2Mg₃⁺²N₂⁻³
Mg⁰ - 2e⁻  ⇒      Mg⁺²  2      3 восстановитель 
                                          6
2N⁰ +2x3e⁻ ⇒    2 N⁻³ 6      1окислитель

2. 2KMn⁺⁷O₄⁻² = K₂Mn⁺⁶O₄ + Mn⁺⁴O₂ + O₂⁰
Mn⁺⁷ + 1e⁻ ⇒   Mn⁺⁶                окислитель
Mn⁺⁷ + 3e⁻ ⇒   Mn⁺⁴  3         2 окислитель
                                           8     
O⁻²    -  2e   ⇒  O⁰      2          4 восстановитель  

3. 4Ag⁰ + O₂⁰ =  2Ag₂⁺O⁻²
Ag⁰- 1e⁻    ⇒   Ag⁺ 1        4 восстановитель
                                     4
2O + 2x2e⁻ ⇒ O⁻²  4        1 окислитель

5. 2Cr⁰ + 3Cl₂⁰  = 2Cr⁺³Cl₃⁻
Cr⁰-3e⁻ ⇒   Cr⁺³    3      2  восстановитель  
                                    6     
2Cl⁰+2x1e⁻ ⇒ Cl⁻ 2      3окислитель

6. H₂S⁻² + Cl₂⁰ = S⁰ + 2HCl⁻
S⁻²  - 2e⁻  ⇒    S⁰    2      1   восстановитель
                                       2
2Cl +2x1e⁻⇒  Cl⁻    2      1 окислитель

Answer 2

Balancing Redox Reactions

Balancing redox reactions involves identifying the oxidation and reduction half-reactions and balancing the number of electrons transferred. Let's go through each of the given reactions and balance them.

1. Mg + N2 -> Mg3N2 - This is a synthesis reaction where magnesium reacts with nitrogen to form magnesium nitride. - The oxidation state of magnesium changes from 0 to +2, and the oxidation state of nitrogen changes from 0 to -3. - The balanced equation for the oxidation half-reaction is: Mg -> Mg^2+ + 2e^- - The balanced equation for the reduction half-reaction is: N2 + 6e^- -> 2N^3- - The overall balanced redox reaction is: 3Mg + N2 -> Mg3N2

2. KMnO4 -> K2MnO4 + MnO2 + O2 - This reaction involves the decomposition of potassium permanganate into potassium manganate, manganese dioxide, and oxygen gas. - The oxidation state of manganese changes from +7 to +6, and the oxidation state of oxygen changes from -2 to 0. - The balanced equation for the oxidation half-reaction is: 4O2- -> 2O2 + 4e^- - The balanced equation for the reduction half-reaction is: Mn^7+ + e^- -> Mn^6+ - The overall balanced redox reaction is: 2KMnO4 -> K2MnO4 + MnO2 + O2

3. Ag + O2 -> Ag2O - This is the formation of silver oxide from the reaction of silver with oxygen. - The oxidation state of silver changes from 0 to +1, and the oxidation state of oxygen changes from 0 to -2. - The balanced equation for the oxidation half-reaction is: 2Ag -> 2Ag^+ + 2e^- - The balanced equation for the reduction half-reaction is: O2 + 4e^- -> 2O^2- - The overall balanced redox reaction is: 4Ag + O2 -> 2Ag2O

4. Ag + O2 -> K2MnO4 + MnO2 + O2 - This reaction seems to be a combination of the previous reactions, which is not balanced as written. - To balance this reaction, the specific reaction conditions and compounds involved need to be clarified.

5. Cr + Cl2 -> CrCl3 - This is the reaction of chromium with chlorine to form chromium(III) chloride. - The oxidation state of chromium changes from 0 to +3, and the oxidation state of chlorine changes from 0 to -1. - The balanced equation for the oxidation half-reaction is: 3Cl^- -> 3/2Cl2 + 3e^- - The balanced equation for the reduction half-reaction is: Cr -> Cr^3+ + 3e^- - The overall balanced redox reaction is: 6Cr + 3Cl2 -> 6CrCl3

6. H2S + Cl2 -> S + HCl - This is the reaction of hydrogen sulfide with chlorine to form sulfur and hydrogen chloride. - The oxidation state of sulfur changes from -2 to 0, and the oxidation state of chlorine changes from 0 to -1. - The balanced equation for the oxidation half-reaction is: S^2- -> S + 2e^- - The balanced equation for the reduction half-reaction is: Cl2 + 2e^- -> 2Cl^- - The overall balanced redox reaction is: H2S + 2Cl2 -> S + 2HCl

These balanced redox reactions demonstrate the transfer of electrons between reactants, with the oxidation and reduction half-reactions balanced to ensure conservation of charge.