Electron transfer reactions

Chemia IBPaper 2, maj 2026, TZ1wzorowane5 pktotwarteśrednie (szac.)

Zadanie 1b

The second step converts nitrogen monoxide to nitrogen dioxide. 2 NO(g) + O₂(g) ⇌ 2 NO₂(g) ΔH^⊖ = −114 kJ mol⁻¹ (i) Identify the oxidation state of nitrogen in NO and in NO₂. (ii) State the equilibrium constant…

Chemia IBPaper 2, maj 2026, TZ1wzorowane1 pktotwarteśrednie (szac.)

Zadanie 1e

Many rechargeable batteries use an alkaline electrolyte. In the nickel-cadmium cell, cadmium, Cd, is the anode. Cd(OH)₂(s) + 2 e⁻ → Cd(s) + 2 OH⁻(aq) NiO(OH)(s) + H₂O(l) + e⁻ → Ni(OH)₂(s) + OH⁻(aq) Deduce the overall reaction for the cell.

Chemia IBPaper 2, maj 2026, TZ1wzorowane4 pktotwarteśrednie (szac.)

Zadanie 1f

Energy can also be produced by a hydrogen-oxygen fuel cell that uses an aqueous solution of sodium hydroxide as the electrolyte. Hydrogen gas is fed to the anode and oxygen gas to the cathode. (i) Deduce the half-equations for the electrode reactions in this…

Chemia IBPaper 1B, maj 2026, TZ1wzorowane2 pktotwarteśrednie (szac.)

Zadanie 2a

(a) Outline two features of this experiment that ensure that the propanal intermediate is not a major product.

• Materiał graficzny

Chemia IBPaper 2, maj 2026, TZ2wzorowane3 pktotwartełatwe (szac.)

Zadanie 2b

An ‘iodine clock’ experiment can be based on two reactions that occur at the same time. S₂O₈²⁻(aq) + 2 I⁻(aq) → 2 SO₄²⁻(aq) + I₂(aq) slow 2 S₂O₃²⁻(aq) + I₂(aq) → S₄O₆²⁻(aq) + 2 I⁻(aq) fast The iodine formed in the slow reaction is removed at…

Chemia IBPaper 1B, maj 2026, TZ3wzorowane5 pktotwarteśrednie (szac.)

Zadanie 2c

The ascorbic acid in the juice was determined by titration with a standard solution of iodine, I₂. The method is based on the following redox reaction: C₆H₈O₆(aq) + I₂(aq) → C₆H₆O₆(aq) + 2 I⁻(aq) + 2 H⁺(aq) (i) Deduce the oxidizing agent in this…

Chemia IBPaper 2, maj 2026, TZ1wzorowane1 pktotwartełatwe (szac.)

Zadanie 3d

Pentan-2-ol will react with acidified potassium dichromate, K₂Cr₂O₇, which is an oxidizing agent. State the name of the product of this reaction.

Chemia IBPaper 2, maj 2026, TZ3wzorowane5 pktotwarteśrednie (szac.)

Zadanie 3d

Iron and nickel can be used to design a voltaic cell. Fe(s) + Ni²⁺(aq) → Fe²⁺(aq) + Ni(s) (i) Annotate the diagram with the appropriate electrodes, electrolyte solutions and the direction of electron flow. (ii) The redox reactions in some voltaic…

• Materiał graficzny

Chemia IBPaper 2, maj 2026, TZ2wzorowane4 pktotwartełatwe (szac.)

Zadanie 4a

Compound X is a flavour compound that occurs in many plants. Its structure is shown below. (i) State the IUPAC name of compound X. (ii) State the name of the functional group represented by the C=O bond itself in compound X. (iii) Predict the size of the H–C=O…

• Materiał graficzny

Chemia IBPaper 1A, maj 2026, TZ3wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 17

Which option describes the electrode reactions in a hydrogen fuel cell with an acidic electrolyte? 2 H₂(g) + O₂(g) → 2 H₂O(l) A. Cathode: hydrogen is oxidized; anode: oxygen is reduced B. Cathode: oxygen is reduced; anode: hydrogen is oxidized C.…