Cambridge Past Paper Questions
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Hydrogen peroxide decomposes slowly at 20 °C to form water and oxygen. 2H2O2 ⇌ 2H2O + O2 equilibrium constant = Kc The reaction is faster when a ...
A dimer, Q, is stable when solid but a dynamic equilibrium is set up in solution. Q(aq) ⇌ 2R(aq) A solution of Q has an initial concentration of ...
The reaction pathway for the forward reaction of a reversible reaction is shown. [Figure 9.1] Which statement is correct?
The enthalpy changes for the possible reactions W, X, Y and Z are given. W NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) ∆H = −56 kJ mol⁻¹ X NaCl(aq) + H...
The Haber process is carried out with a nitrogen partial pressure of 50 kPa, a hydrogen partial pressure of 150 kPa, a temperature of 400 °C and an...
The compound (CH3)3NAlCl3 has a simple molecular structure. Which statement about (CH3)3NAlCl3 is correct?
VSEPR theory should be used in answering this question. The dot-and-cross diagram for an ozone, O3, molecule is shown. [Figure 13.1] What is the...
Each of the substances shown is gaseous. Which substance is most likely to show ideal behaviour in the conditions shown? [Table 14.1: substance, ...
Which graph represents the variation of pressure p and volume V of a sample of an ideal gas at constant temperature?
Use relevant enthalpy changes from the tables to answer this question. [Table 16.1: Reactions and ∆H/kJ mol⁻¹] [Table 16.2: Bond and bond enthalpy...
Element X requires strong heating to react with oxygen. Element X reacts with chlorine to give a covalently-bonded chloride. What could be the ide...
The melting points of the Period 3 elements sodium to aluminium are shown in the table. [Table 18.1: element, melting point/K] Which factor expla...
The nitrates of beryllium, calcium, magnesium and strontium all decompose in the same way when heated. When 2.00 g of one of these anhydrous nitrat...
In the diagram, each test-tube W, X, Y and Z contains 25 cm³ of a 0.1 mol dm⁻³ solution of a salt. [Figure 20.1] To test-tubes W and X, 25 cm³ of...
What is the oxidation state of the chlorine-containing species that kills bacteria in drinking water?
Compound Q is a white crystalline solid which dissolves easily in water. When concentrated sulfuric acid is added to a dry sample of Q, steamy whi...
R is a solid. R fizzes when hydrochloric acid is added. R reacts with hot aqueous sodium hydroxide, giving off a gas which turns red litmus blue. ...
Photochemical smog is a type of air pollution produced in urban areas by the effect of sunlight on substances released from vehicle exhausts. Whic...
T is an element in Period 3. The first ionisation energy of T is lower than that of the element with one less proton. The oxide of T does not rea...
The structure of tartaric acid is shown. [Figure 26.1] Which statements about tartaric acid are correct? 1 A molecule of tartaric acid has more ...
A carboxylic acid, P, has no chain isomers. It reacts with an alcohol, Q, that has only one positional isomer. What could be the ester formed from...
Which pair includes a hydrocarbon without a chiral centre?
What is the major product formed when compound R is warmed with an excess of HBr? [Figure 29.1] [Figure 29.2]
cis-but-2-ene reacts with cold dilute acidified potassium manganate(VII) solution to give product X. cis-but-2-ene reacts with hot concentrated ac...
For which reaction will the major organic product have the lowest relative molecular mass?
C4H9Cl reacts with warm dilute aqueous sodium hydroxide solution. Which isomer of C4H9Cl will form the most stable cation intermediate?
1.0 mol of an organic compound, J, requires 6.0 mol of oxygen for complete combustion. 1.0 mol of J reacts with sodium, producing 0.50 mol of a ga...
Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot concentrated sulfur...
The table shows a student's predictions for the reactions of three compounds. [Table 35.1: Predictions for reactions] Which rows show the correct...
Which mechanism describes the reaction of aldehydes and ketones with HCN + NaCN?
Propyl propanoate can be synthesised in three steps using propanenitrile as the only organic starting material. In step 1, the nitrile is converte...
The ester CH3CH2CO2CH3 is hydrolysed by boiling with aqueous sodium hydroxide. Which compound is one of the products?
Compound V polymerises to form polymer W. A section of polymer W is shown. [Figure 39.1] What is the correct name of compound V?
A molecule of an organic compound, P, contains three carbon atoms and shows a strong absorption at 1720 cm⁻¹ in its infrared spectrum. P is reacte...
Atoms with nuclei containing an odd number of protons tend to have fewer isotopes than those with an even number of protons.
Magnesium shows reactions typical of a Group 2 metal.
Some of the common chlorides of Period 3 elements are shown in the list. NaCl MgCl2 AlCl3 SiCl4 PCl5
Organic compounds can be distinguished using chemical tests. Table 4.1 shows four pairs of compounds. [Table 4.1 showing pairs A1/A2, B1/B2, C1/C2,...
Lactones are cyclic esters. Under suitable conditions, lactones form from molecules that have both an alcohol and a carboxylic acid functional grou...
Species such as NH4+, CO32- and PO43- are examples of molecular ions.
The chlorides of some of the Period 3 elements are shown in Table 2.1. [Table 2.1]
Organic compounds can be distinguished using chemical tests and analytical techniques. [Table 3.1]
Hydrated copper(II) sulfate, CuSO4•5H2O, can lose its water of crystallisation to form anhydrous copper(II) sulfate. The enthalpy change for the de...
2 In this experiment you will determine the percentage by mass of magnesium in a hydrated salt, MgX•7H2O, where X represents the anion. You will m...
Potassium chloride, KCl, and magnesium chloride, MgCl2, are both ionic solids. [Table 1.1] energy change value/kJ mol-1 standard enthalpy c...
Data should be selected from [Table 3.1] in order to answer some parts of this question. [Table 3.1] electrode reaction E° / V Cl2 + 2e- ⇌ ...
A transition element is a d-block element which forms one or more stable ions with incomplete d-orbitals.
An aqueous solution of copper(II) sulfate is a blue colour due to the presence of [Cu(H2O)6]2+ complex ions.