9.1 A simplified diagram of an electrical machine is shown below. 9.1.1 Is this machine a DC motor or a DC generator? (1) 9.1.2 Write down the energy conversion that takes place while thismachine is in operation. (2) 9.1.3 Write down the name of component A in the diagram. (1) 9.1.4 In which direction will … Read more
A battery with an internal resistance of 0,5 Ω and an unknown emf (ε) is connected tothree resistors, a high resistance voltmeter and an ammeter of negligible resistance, asshown in the circuit diagram below. 8.1 Define the term emf of a battery. (2) The reading on the voltmeter DECREASES by 1,5 V when switch S … Read more
Two small charged spheres, A and B, are placed on insulated stands, 0,2 m apart, asshown in the diagram below. They carry charges of −4 x 10-6 C and +3 x 10-6 Crespectively. M is a point that is a distance of 0,1 m to the right of sphere B. 7.1 Calculate the number of … Read more
10.1 The flow diagram below shows how fertiliser B is produced in industry. Write down the: 10.1.1 NAME of S (1) 10.1.2 NAME of T (1) 10.1.3 NAME or FORMULA of the catalyst used in process 1 (1) 10.1.4 NAME or FORMULA of compound A (1) 10.1.5 NAME of process 2 (1) 10.1.6 Balanced equation … Read more
The simplified diagram below represents an electrolytic cell used to electroplate acopper (Cu) coin with silver (Ag). 9.1 Define the term electrolysis. (2) 9.2 Which component in the diagram indicates that this is an electrolytic cell? (1) 9.3 Write down the NAME or FORMULA of the electrolyte. (1) 9.4 How will the concentration of the … Read more
The electrochemical cell illustrated below is set up under standard conditions 8.1 Component X completes the circuit in the cell. State ONE other function of component X. (1) 8.2 Define the term anode. (2) 8.3 Identify the anode in the cell above. (1) 8.4 Write down the: 8.4.1 Reduction half-reaction that takes place in this … Read more
7.1 Ethanoic acid (CH3COOH) is an ingredient of household vinegar 7.1.1 Is ethanoic acid a WEAK acid or a STRONG acid? Give a reason for the answer. (2) 7.1.2 An ethanoic acid solution has a pH of 3,85 at 25 °C. Calculate the concentration of the hydronium ions, H3O+(aq), in the solution. (3) Sodium ethanoate, … Read more
The dissociation of iodine molecules to iodine atoms (I) is a reversible reaction takingplace in a sealed container at 727 °C. The balanced equation for the reaction is Kc for the reaction at 727 °C is 3,76 x 10-3 6.1 Write down the meaning of the term reversible reaction (1) 6.2 At equilibrium the pressure … Read more
The reaction of calcium carbonate (CaCO3) and EXCESS dilute hydrochloric acid(HCℓ) is used to investigate one of the factors that affects reaction rate. The balancedequation for the reaction is: The same mass of CaCO3 is used in all the experiments and the temperature of thehydrochloric acid in all experiments is 40 °C. The reaction conditions … Read more