Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
2 The reaction between thiosulfate ions and hydrogen ions produces a precipitate of sulfur. When the concentration of hydrogen ions, [H+(aq)], is k...
Aqueous acidified iodate(V) ions, IO3¯, react with iodide ions, as shown. IO3¯ + 6H+ + 5I¯ → 3I2 + 3H2O The initial rate of this reaction is invest...
Group 2 carbonates decompose when heated to form the metal oxide and carbon dioxide.
Aqueous solutions of cobalt(II) salts contain the complex ion [Co(H2O)6]2+.
Table 3.2 shows some energy changes. [Table 3.2]
In aqueous solution, iron(III) ions react with iodide ions, as shown. 2Fe3+ + 2I- → 2Fe2+ + I2 A series of experiments is carried out using differe...
Methylbenzene can undergo different reactions, as shown in Fig. 5.1. [Figure 5.1]
Perindopril is a drug used to treat heart disease. [Figure 6.1, structure of perindopril]
Fig. 7.1 shows some reactions of phenol. [Figure 7.1]
Compound T, C5H9O2Cl, is a useful synthetic intermediate. Fig. 8.1 shows some reactions of T. [Figure 8.1]
An electrochemical cell is set up to measure E°cell of a cell consisting of an Fe3+ /Fe2+ half-cell and a Cl2/Cl- half-cell. Include all necessary ...
Some transition element complexes can show stereoisomerism.
Compound H has the structural formula CH2=CHCH(NH2)COOH.
Complete Table 8.1 by placing one tick (✔) in each row to indicate the sign of each type of energy change under standard conditions. [Table 8.1]
The partition coefficient, Kpc, shows the distribution of a solute between two immiscible solvents. Kpc is determined by measuring the concentratio...
Paper chromatography can be used to separate the individual amino acids formed when tripeptides are hydrolysed. One molecule of a tripeptide produc...
A scientist is asked to find the rate of decomposition of an aromatic diazonium compound and determine the order of the reaction with respect to th...
Three students are asked to prepare samples of benzoic acid, C6H5COOH, from the alkaline hydrolysis of methyl benzoate, C6H5COOCH3. Sodium benzoate...
Pure water dissociates according to the equation shown. H₂O(l) ⇌ H⁺(aq) + OH⁻(aq) The equilibrium constant for this reaction is known as Kʷ, the ...
Which pair of formulae is correct?
How many molecules are present in 62 g of solid white phosphorus, P4?
In which pairs are both species free radicals? 1 Cl and O 2 Cl⁻ and O²⁻ 3 Cl and O 4 Cl⁺ and O²⁺
Which shape is correctly predicted by VSEPR theory? [Table 5.1]
In this question it should be assumed that nitrogen behaves as an ideal gas under the conditions stated. Which volume is occupied by 1.00 g of nitr...
Consider the following four compounds. 1 (CH3)3CH 2 CH3CH2CH2OH 3 CH3CH2CH2SH 4 CH3CH2CH2CH3 What is the order of increasing boiling point of the c...
Ethane can react with fluorine to produce 1,2-difluoroethane, C2H4F2. C2H6 + 2F2 → C2H4F2 + 2HF ∆H = −960 kJ mol⁻¹ [Table 9.1] What is the bond ene...
Which equation has an enthalpy change equal to the standard enthalpy of formation of sodium oxide?
Nitrogen dioxide reacts with water. 2NO2 + H2O → HNO2 + HNO3 Which statement about this reaction is correct?
Phosphorus reacts with concentrated sulfuric acid to produce phosphoric acid, sulfur dioxide and water. aH2SO4 + bP → CH3PO4 + dSO2 + eH2O a, b, c,...
The volume of ammonia produced against time is measured in two experiments. N2(g) + 3H2(g) ⇌ 2NH3(g) ∆H = −92 kJ mol⁻¹ In experiment 1, 3 mol of H2...
Which reaction has an equilibrium constant, Kp, that has no units?
Gas Q decomposes slowly at room temperature. Q(g) → X(g) + Z(g) The Boltzmann distribution curve for gas Q at room temperature is shown. [Figure 15...
A mixture of calcium carbonate, calcium nitrate, strontium carbonate and strontium nitrate is thermally decomposed. The decomposition reaction of e...
W is a solid that reacts with water to produce an alkaline solution. The addition of two drops of dilute H2SO4 to this alkaline solution produces a...
Chlorine gas is reacted with cold aqueous sodium hydroxide. Which statement is correct for this reaction?
Sodium is added to water to form solution Y. The pH of solution Y is measured. When powdered substance X is added to solution Y, the pH falls. Whic...
The table shows statements about some of the properties of halogens and their compounds and explanations for these properties. [Table 21.1] Which r...
Which statement describes a property of an ammonium ion?
Catalytic converters are fitted in the exhaust systems of many cars. Gas X: • causes acid rain if it is released into the air • is removed from car...
In the general formula of which class of compound is the ratio of hydrogen atoms to carbon atoms the highest?
Z is a gaseous hydrocarbon which has a density of 3.50 × 10⁻³ g cm⁻³ under room conditions. Z reacts with an excess of hot concentrated acidified K...
Compound X can be oxidised to compound Y. Compound Y gives a yellow precipitate with alkaline I2(aq). What is compound X?
Aqueous NaOH reacts with 1-bromopropane to give propan-1-ol. What should be included in a diagram of the first step in the mechanism?