grade12

1.1 Inertia is the tendency of an object to … A maintain its mass.B continue in a state of non-uniform motion.C remain at rest or in the state of uniform motion.D maintain its velocity when a non-zero net force is acting on it. (2) 1.2 A person stands on a bathroom scale that is fixed … Read more

QUESTION 10 (Start on a new page.) The flow diagram below shows the processes involved in the industrial preparation ofan ammonium fertiliser. 10.1 Write down the NAME or FORMULA of: 10.1.1 Gas X (1) 10.1.2 Gas Y (1) 10.1.3 Acid Q (1) 10.2 Write down the: 10.2.1 TYPE of chemical reaction that converts compound P … Read more

QUESTION 9 (Start on a new page.) Chlorine is produced industrially by the electrolysis of a concentrated sodium chloridesolution, NaCℓ(aq). The balanced equation for the net (overall) cell reaction is as follows: 9.1 Define the term electrolysis. (2) 9.2 For the above reaction, write down the: 9.2.1 Half-reaction that takes place at the cathode (2) … Read more

QUESTION 8 (Start on a new page.) A standard electrochemical cell is set up using two standard half-cells, as shown in thediagram below. 8.1 State the energy conversion that takes place in this cell. (1) 8.2 What is the function of component Q? (1) X is a metal. A voltmeter connected across the cell initially … Read more

QUESTION 7 (Start on a new page.) A hydrogen bromide solution, HBr(aq), reacts with water according to the followingbalanced chemical equation: The Ka value of HBr(aq) at 25 °C is 1 x 109. 7.1 Is hydrogen bromide a STRONG ACID or a WEAK ACID? Give a reason for the answer. (2) 7.2 Write down the … Read more

QUESTION 6 (Start on a new page.) Initially 60,8 g pure carbon dioxide, CO2(g), is reacted with carbon, C(s), in a sealedcontainer of volume 3 dm3. The reaction reaches equilibrium at temperature Taccording to the following balanced equation: 6.1 Define the term chemical equilibrium. (2) 6.2 At equilibrium it is found that the concentration of … Read more

QUESTION 5 (Start on a new page.) The calcium carbonate (CaCO3) in antacid tablets reacts with dilute hydrochloric acid(HCℓ) according to the following balanced equation: 5.1 Is the above reaction EXOTHERMIC or ENDOTHERMIC? Give a reason for the answer. (2) An antacid tablet of mass 2 g is placed in HCℓ(aq). After 30 s the … Read more

QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are provided as possible answers to the following questions. Choose theanswer and write only the letter (A–D) next to the question numbers (1.1 to 1.10) inthe ANSWER BOOK, e.g. 1.11 E. 1.1 Which ONE of the following compounds has the HIGHEST vapour pressure? A HCOOH B CH3CHO C CH3CH2OH … Read more

During an experiment, light of different frequencies is radiated onto a silver cathode of  a photocell and the corresponding maximum speed of the ejected photoelectrons are measured. A graph of the energy of the incident photons versus the square of the maximum speed of the ejected photoelectrons is shown below. 10.1 Define the term photoelectric … Read more

9.1 A simplified diagram of an electric generator is shown below. When the coil is  rotated with a constant speed, an emf is induced in the coil. 9.1.1 Is this an AC generator or a DC generator?        (1) 9.1.2 Briefly explain how an emf is generated in the coil when the coil is rotated by referring … Read more