9 th SA-2 Solved Practice paper [Physics and Chem istry] 2014 1. Name the anion and cation which constitute the molecule of magnesium oxide [1] 2. A cube of side 5cm is immersed in water and then in saturated salt solution. In which case will it experience a greater buoyant force. If each side of the cube is reduced to 4cm and then immersed in water compare the force experienced by the cube, as compared to the first case. Give reasons for each case. 2 3. The kinetic energy of an object of mass `m� moving with a velocity of 5ms-1 is 25J. Calculate its kinetic energy when its velocity is doubled. 2 4. The percentage of three elements calcium, carbon and oxygen in a sample of calcium carbonate is given as : [3] Calcium =40% ; Carbon =12.0% ; Oxygen = 48% If the law of constant proportion is true, what weights of these elements will be present in 1.5 g of another sample of calcium. Carbonate ? (Atomic mass of Ca = 40 u , C =...