Exam (elaborations) Chemistry Assessment2120

1. Which one of the following elements reacts with nitrogen when heated? A. Copper. B. Zinc. C. Sulphur. D. Magnesium. 2. The reaction in which vegetable oil is changed to margarine is called A. dehydration. B. hydrogenation. C. hydration. D. saponification. 3. Ethene was bubbled through a solution of bromine in tetrachloromethane. The structure of the compound formed is A. B. C. D. 4. Element X belongs to group II in the Periodic Table. The formula of the oxide of X is A. XO. B. X2O. C. X2O3. D. XO2. 5. The mass of potassium hydroxide, KOH, contained in 250cm3 of 0.01 M of potassium hydroxide solution is (K=39; H=1; O=16) A. 0.056 g. B. 0.140 g. C. 0.280 g. D. 0.560 g. 6. Which one of the substances underlined in the equations below is being reduced? A. PbO(s) + H2(g)  Pb(s) + H2O(l). B. 2SO2(g) + O2(g)  2SO3(g). C. H2S(g) + Cl2(g)  S(s) + 2HCl(g). D. 2NH3(g) + 3CUO(s)  3Cu(s) + 3H2O(l) + N2(g). 7. The number of particles in the nuclei of atoms Q, R, S and T are shown in the table below Atom Number of Particles Protons + Neutrons Neutrons Q 40 20 R 40 22 S 45 24 T 45 25 Which of the atoms are isotopes? A. Q and R. B. Q and T. C. R and S. D. S and T. 8. A salt P reacted with concentrated sulphuric acid to give a colourless gas which fumed in moist air. The anion in P is likely to be a A. nitrate. B. chloride. C. sulphite. D. carbonate. 9. The breakdown of starch into glucose when heated in solution with dilute acid is known as A. dehydration. B. fermentation. C. hydrolysis. D. hydrogenation. 10. Which one of the graphs below shows the change in mass of calcium carbonate with time when it is reacted with hydrochloric acid? A. (i). B. (ii). C. (iii). D. (iv). 11. The reaction in which ethanol is changed to ethene when ethanol is reacted with excess concentrated sulphuric acid is called A. hydrogenation. B. neutralisation. C. hydration. D. dehydration. 12. Ethane burns in oxygen according to the following equation 2C2H6 + xO2  yCO2 + 6H2O. The values of x and y in the equation are A. x=2 and y=2. B. x=7 and y=6. C. x=7 and y=4. D. x=4 and y=6. 13. Which one of the following anions will react with silver nitrate solution to give a white precipitate soluble in excess aqueous ammonia? A. Cl-. B. NO 3  . C. SO 4 2  . D. CO 3 2  . 14. Which one of the following oxides would dissolve in excess aqueous ammonia and in excess dilute sodium hydroxide solution? A. FeO. B. ZnO. C. CuO. D. PbO. 15. 10 g of a saturated sodium chloride solution was evaporated and 6 g of solid sodium chloride was left. The solubility of sodium chloride is A. ) 10 6 100 ( x B. ) 4 6 100 ( x C. ) 16 6 100 ( x D. ) 16 10 100 ( x 13. Which one of the following anions will react with silver nitrate solution to give a white precipitate soluble in excess aqueous ammonia? A. Cl-. B. NO 3  . C. SO 4 2  . D. CO 3 2  . 14. Which one of the following oxides would dissolve in excess aqueous ammonia and in excess dilute sodium hydroxide solution? A. FeO. B. ZnO. C. CuO. D. PbO. 17. A compound contains Fe, 72.4% and O, 27.6%. (Fe=56= O=16). The empirical formula of X is given by the ratio A. ) 72 72.4 ( : ) 72 27.6 ( B. ) 56 72.4 ( : ) 16 27.6