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…
Oxidation, reduction and redox agents
Define oxidation and reduction in terms of electron transfer, change in oxidation state and gain or loss of oxygen or hydrogen, and use oxidation states to identify the species oxidized and reduced and the oxidizing and reducing agents in a reaction.
Tę umiejętność sprawdzają 23 zadania wzorowane na arkuszach IB z lat 2022–2026.
Zadania sprawdzające tę umiejętność: 23 Otwórz w wyszukiwarce z filtrami
Zadanie 32
Which statement about this reaction is correct? 2 Cl2 + O2 → 2 Cl2O A. Chlorine is the reducing agent. B. Oxygen is the reducing agent. C. Chlorine is reduced. D. Oxygen is oxidized.
Zadanie 36
What happens to hydrogen in the following reaction? Each option states whether hydrogen is oxidized or reduced and the change in its oxidation state. Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) A. Oxidized, from +1 to 0 B. Oxidized, from 0 to +1 C. Reduced,…
Zadanie 36
Which statement about this reaction of permanganate ions with iron(II) ions is correct? MnO4−(aq) + 5 Fe2+(aq) + 8 H+(aq) → Mn2+(aq) + 5 Fe3+(aq) + 4 H2O(l) A. MnO4− is the reducing agent B. Fe3+ is reduced C. The oxidation state of…
Zadanie 38
Which change represents oxidation of the functional group? A. CH3COCH3 → CH3CH(OH)CH3 B. CH3CH(OH)CH3 → CH3COCH3 C. CH3CH2COOH → CH3CH2CHO D. CH3CH=CH2 → CH3CH2CH3
Zadanie 33
Which row identifies the oxidizing agent and the reducing agent in the reaction below? 3 Cu(s) + 2 NO3−(aq) + 8 H+(aq) → 3 Cu2+(aq) + 2 NO(g) + 4 H2O(l) A. Oxidizing agent: Cu, reducing agent: NO3− B. Oxidizing agent: NO3−, reducing…
Zadanie 1a
Deduce the oxidation state of chlorine in each of the three chlorine-containing species in the equation. Cl2: HOCl: Cl−:
Zadanie 34
The overall reaction during the discharge of a lead–acid battery is: Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l) Which statement is correct? A. The oxidation state of lead in Pb(s) changes from +2 to 0. B. The oxidation state of sulfur…
Zadanie 4a
(i) State the oxidation states of carbon in carbon monoxide and in carbonyl chloride. (ii) For each of CO and Cl2 in the forward reaction, state whether it acts as an oxidizing agent or a reducing agent, and whether it is oxidized or reduced.
Zadanie 32
The concentration of hypochlorite ions in bleach can be determined in two stages. Stage I: ClO−(aq) + 2 I−(aq) + 2 H+(aq) → Cl−(aq) + I2(aq) + H2O(l) Stage II: I2(aq) + 2 S2O32−(aq) → 2 I−(aq) + S4O62−(aq) Which of the following is correct? A.…
Zadanie 7a
Identify the species that is oxidized in step 2 and give a reason.
Zadanie 28
In which reaction does N2 act as a reducing agent? A. N2(g) + 3 H2(g) → 2 NH3(g) B. 3 Mg(s) + N2(g) → Mg3N2(s) C. N2(g) + O2(g) → 2 NO(g) D. 6 Li(s) + N2(g) → 2 Li3N(s)
Zadanie 2a
All the species in the titration are almost colourless except MnO4−, which is intensely purple. The spinach extract, however, is coloured green by chlorophyll. (i) State the colour change at the end point. (ii) Outline how adding distilled water to the…
Zadanie 28
Which change involves the oxidation of chlorine? A. Cl2 → Cl− B. ClO4− → ClO3− C. Cl2 → ClO3− D. HCl → Cl−
Zadanie 28
Which species is the reducing agent in the following reaction? 2 MnO4−(aq) + 5 SO32−(aq) + 6 H+(aq) → 2 Mn2+(aq) + 5 SO42−(aq) + 3 H2O(l) A. MnO4− B. H+ C. Mn2+ D. SO32−
Zadanie 1d
The vitamin C content of a juice can be found by titrating a sample against a standard iodine solution. Starch is used as the indicator: it forms a dark blue-black complex with the first excess of iodine once all the vitamin C has reacted.…
Zadanie 1d
The concentration of vitamin C in juice can be measured by a redox titration. A sample of acidified juice containing excess iodide ions and starch solution is titrated with potassium iodate solution. Iodate ions react with iodide ions to produce iodine…
Zadanie 29
Zinc reacts with an aqueous solution of ethanoic acid. Zn(s) + 2 CH3COOH(aq) → Zn(CH3COO)2(aq) + H2(g) Which combination shows the role of the acid and the gas formed? A. oxidizing agent, H2(g) B. oxidizing agent, CO2(g) C. reducing agent,…
Zadanie 29
Magnesium ribbon is added to aqueous ethanoic acid. Which combination gives the role of the acid and a product formed from it? A. Oxidizing agent, H2(g) B. Oxidizing agent, CO2(g) C. Reducing agent, H2(g) D. Reducing agent, CO2(g)
Zadanie 1d
The presence of calcium nitride in the product can be demonstrated by adding water. The nitride is hydrolysed to form calcium hydroxide and ammonia. (i) Calculate coefficients that balance the equation for the reaction: __ Ca3N2(s) + __ H2O(l) →…
Zadanie 1c
Identify the oxidizing agent in the reaction of sodium with water and justify your answer in terms of oxidation states.
Zadanie 28
In which species would nitrogen be oxidized if it were converted to N2O? A. NO2 B. NH4+ C. HNO3 D. N2O3
Zadanie 28
Which combination best describes what is happening to propene, CH3CH=CH2, in the equation below? CH3CH=CH2(g) + H2(g) → CH3CH2CH3(g) A. Oxidation and addition B. Oxidation and substitution C. Reduction and addition D. Reduction and substitution