8.1 Two reactions of sulphuric acid are shown in the diagram below. 8.1.1 Define a Lowry-Brønsted base.(2) 8.1.2 Write down a balanced equation for Reaction 1.(3) 8.1.3 Write down the NAME of the salt represented by X.(2) 8.1.4 Write down the FORMULA of ampholyte A.(2) 8.1.5 Write down the formulae of the TWO conjugate acid-base … Read more
When sulphuric acid reacts with water, it ionises in two steps, as shown in the two balanced equations below. 8.1 Define an acid in terms of the Lowry-Brønsted theory. (2) 8.2 Write down the FORMULA of: 8.2.3 A substance that acts as ampholyte in these reactions (1) 8.3 A few drops of bromothymol blue indicator … Read more
8.1 A bag contains 3 blue marbles and 2 red marbles. A marble is taken from the bag the colour is recorded and the marble is put aside. A second marble is taken from the bag the colour is recorded and then put aside 8.1.1 Draw tree diagram to represent the information above. Show the … Read more
Two IDENTICAL point charges, X and Y, are placed 2 mm apart. Point P is 3 mm to the right of charge Y. The net electric field at point P is 5,44 × 106 N∙C-1 to the left. 8.1 Define the term electric field at a point. (2) 8.2 Are the charges NEGATIVE or POSITIVE? … Read more
The sketch below shows the graph of f(x) = 2 x ax – 1. The point A(1; 5) is a point on the graph. 8.1 Show that a = 3. (2) 8.2 Determine the y-intercept of f . (2) 8.3 Write down the range of f . (1) 8.4 Determine f (0,23), rounded off to … Read more
GIVE REASONS FOR YOUR STATEMENTS AND CALCULATIONS IN QUESTIONS 8, 9, 10 AND 11. 8.1 Complete: The line drawn from the centre of the circle perpendicular to the chord … (1) 8.2 In the figure below, AB and CD are chords of the circle with centre O. OE â”´ AB. CF = FD. OE = … Read more
8.1 A new cell phone was purchased for R 7 200. Determine the depreciation value after 3 years if the cell phone depreciates at 25% per annum on reducing balance method. (3) 8.2 An amount of R 500 is invested at x % per annum compounded half yearly. After 6 years it has grown to … Read more
Give reasons for ALL statements in QUESTIONS 8, 9 and 10. In the diagram below O is the centre of the circle. Quadrilateral ABCO is drawn with A and C on the circumference. AB is a tangent to the circle at point A and BC is a tangent to circle at point C. D is … Read more
Your teacher asked you to use your knowledge of precipitation reactions to test the quality of water in the local river. You are provided with the following chemicals: AgNO3, BaCl2, dilute HNO3 8.1 Which chemical would you choose to test for the presence of carbonates (CO3-2)? (1) 8.2 Use a balanced chemical equation to show … Read more