8.1 Corrosion is a redox reaction that takes place in the presence of oxygen and water. Rusting is the corrosion of iron leading to the formation of iron(III) ions. 8.1.1 Define oxidation in terms of electron transfer. (2) A cleaned copper rod and a cleaned iron nail are placed in a beaker containing water at … Read more
7.1 Sulphuric acid is a strong acid present in acid rain. It ionises in two steps as follows: 7.1.1 Define an acid in terms of the Lowry-Brønsted theory. (2) 7.1.2 Write down the FORMULA of the conjugate base of H3O+(aq). (1) 7.1.3 Write down the FORMULA of the substance that acts as an ampholyte in … Read more
Dinitrogen tetraoxide, N2O4(g), decomposes to nitrogen dioxide, NO2(g), in a sealed syringe of volume 2 dm3. The mixture reaches equilibrium at 325 °C according to the following balanced equation: When equilibrium is reached, it is observed that the colour of the gas in the syringe is brown. 6.1 State Le Chatelier’s principle. (2) 6.2 The … Read more
The reaction of zinc and EXCESS dilute hydrochloric acid is used to investigate factors that affect reaction rate. The balanced equation for the reaction is: The reaction conditions used and the results obtained for each experiment are summarised in the table below. The same mass of zinc is used in all the experiments. The zinc … Read more
4.1 Three reactions of organic compounds from the same homologous series are shown below. 4.1.1 Define a homologous series. (2) 4.1.2 Name the type of reaction represented by I. (1) 4.1.3 Write down the formula of the inorganic compound P. (1) 4.1.4 Give the structural formula of a POSITIONAL isomer of 2-bromobutane. … Read more
The boiling points of different organic compounds are given below. 3.1 Define boiling point. (2) 3.2 Write down the: 3.2.1 Name of the FUNCTIONAL GROUP of these compounds (1) 3.2.2 IUPAC name of compound C (1) 3.2.3 Structural formula of the FUNCTIONAL isomer of compound B (2) 3.3 Which ONE of … Read more
A test tube containing a straight chain organic acid X, ethanol and a catalyst is heated in a water bath as illustrated below. Organic compound Y is produced according to the following equation: 2.1 Give a reason why the test tube is heated in a water bath instead of directly over the flame. (1) … Read more
1.1 Which ONE of the following is the structural formula of the functional group of the KETONES? 1.2 Which ONE of the formulae below represents an ALKANE? A C2H4 B C5H10 C C14H30 D C8H14 (2) 1.3 Consider the organic compound below. The IUPAC name of this compound is … A 2,3-dimethyl … Read more
10.1 In the simplified AC generator below, the coil is rotated clockwise. 10.1.1 In which direction does the induced current flow in the coil?Choose from: X to Y or Y to X. (1) 10.1.2 On which principle or law is the working of the generator based? (1) 10.1.3 State the energy conversion that takes place … Read more
Learners perform an experiment to determine the emf (ε) and the internal resistance (r)of a battery using the circuit below. 9.1 Which variable has to be kept constant in the experiment? (1) 9.2 Refer to the graph. 9.2.1 Write down the value of the internal resistance of the cell. (2) 9.2.2 Calculate the emf of … Read more