The fertiliser ammonium sulphate ((NH4)2SO4) is produced from the reaction ofsulphuric acid (H2SO4) and ammonia (NH3) according to the balanced equation: 2 kg of sulphuric acid and 58,82 moles of ammonia are available to produce thefertiliser. 7.1 Define the term limiting reagent. (2) 7.2 Calculate the maximum mass of ammonium sulphate that can be produced … Read more
6.1 Methyl propanoate is an organic compound with the following percentagecomposition: 54,55% C ; 9,09% H ; 36,36% O The molar mass of the compound is 88 g∙mol-1. 6.1.1 Define the term empirical formula. (2) 6.1.2 Determine, by calculation, the empirical formula. (6) 6.1.3 Determine the molecular formula. (2) 6.2 Learners prepare a solution of … Read more
Learners study ENDOTHERMIC and EXOTHERMIC reactions by conducting experiments I and II in which the reactions shown in the table below take place. The learners measured the initial and final temperatures of the reaction mixtures.They also obtained activation energies for the reactions from a data table. The learners represented their findings in a table as … Read more
Grade 11 learners want to verify the relationship between temperature and volume of a gas. They used the following experimental set-up. 4.1 Write down the name of the gas law that is investigated. (1) 4.2 For this investigation write down the: 4.2.1 Investigative question (2) 4.2.2 Controlled variable (1) 4.3 Write down the name of … Read more
3.1 The boiling points in the table below were obtained during an investigation carried out to compare the boiling points of group 7 hydrides. The hydrides, HCâ„“ and HBr, are labelled in the table as compounds A and B respectively. 3.1.1 Define the term boiling point. (2) 3.1.2 In what phase are compounds (A and … Read more
Consider the following chemical equations: 2.1 Define the term covalent bond. (2) 2.2 Write down the Lewis structure for the CH4 molecule. (2) 2.3 Consider the bonds C – H and O – H Which bond … 2.3.1 has a longer bond length? Give a reason for your answer. 2.3.2 is stronger? (1) 2.4 How … Read more
10.1 A learner sets up the circuit below to investigate the relationship between current and potential difference across the ends of a conductor. She closes the switch and records the ammeter and voltmeter readings. She repeats the experiment three times; each time she increases the number of cells in the circuit. Then she reads and … Read more
9.1 The diagram below represents a current-carrying conductor. Draw the magnetic field pattern around this conductor. 9.2 A solenoid with a radius of 5 cm and 350 turns is pulled out of a magnetic field of strength 5,20 T in 0,1 second. The solenoid is placed perpendicular to the magnetic field. 9.2.1 State Faraday’s law … Read more
Two identical point charges are placed 100 mm apart in a vacuum as shown below. The electrostatic force that Q1 exerts on Q2 is 5,09 N. 8.1 Draw the electric field pattern between the two charges. (3) 8.2 Calculate the magnitude of each charge. (4) 8.3 Calculate the net electric field at point P, as … Read more