Form-4-Chem-Revision-Objectives.pdf

1. What is the definition of Chemistry? A. Study about the reactions that occur in our daily lives. B. Study about the structures, properties, compositions and interactions between matters. C. Study about mole concept. D. Study about chemicals in daily life. Ans: B 2. The information below show...

1. What is the definition of Chemistry? A. Study about the reactions that occur in our daily lives. B. Study about the structures, properties, compositions and interactions between matters. C. Study about mole concept. D. Study about chemicals in daily life. Ans: B 2. The information below shows four important steps in the scientific method. W – Making observations X – Making inference Y – Making hypothesis Z – Plan an experiment Which of the following sequence of the steps in scientific method is correct while conducting a scientific investigation? A. W, X, Y, Z B. X, Y, W, Z C. Y, X, W, Z D. Z, X, W, Y Ans: A 3. Diagram below shows an example of equipment for personal protection. What is the function of this equipment? A. Used to protect body and clothing from chemical spills such as acids, alkalis and organic solvents. B. Protects the respiratory organs from chemicals in the form of powder or fume. C. Avoid dust or chemicals from coming into contact with the eyes. D. Used for washing and cleaning the eye when accidents occur on parts of the eye. Ans: C 4. Which of the following is not the correct pairs? Field Chemicals A. Food Stabiliser B. Medicine Analgesic C. Agriculture Hormone D. Industry Antioxidant Ans: D 5. Which is the correct disposal method for the following chemicals? A. Throw solid wastes like glass into rubbish bins. B. Pour low concentrated hydrogen peroxide into the laboratory’s sink directly. C. Store hydrocarbons and organic solvents near the window with sunlight because the chemicals are volatile. D. Store strong acid (sulphuric acid) in an unlocked storage cabinet so it is easier for the student to take the solution during the experiment. Ans: B 6. What are the correct procedures to manage emergency case? I. Stop the spill from spreading by using sand to border it. II. Inform teacher or laboratory assistant. III. Make the spill site a restricted area. IV. Clean the chemical spill. A: I, III, IV, II B. II, III, I, IV C. III, I, IV, II D. IV, III, I, II Ans: B 7. Ahmad carried out an experiment to compare the rate of corrosion between an iron nail and a steel nail. Which of the following is the responding variable in the experiment? A. Presence of iron and steel nails B. Presence of water C. Rate of rusting D. Type of nail Ans: C 8. What can you deduce from this graph? A. When temperature decreases, the solubility of sugar decreases B. When temperature decreases, the solubility of sugar increases C. When temperature increases, the solubility of sugar decreases D. When temperature increases, the solubility of sugar increases Ans: D 9. What is Process X? A. Boiling B. Freezing C. Melting D, Sublimation Ans: C 10. Table 1 shows the proton number of elements P, Q, R and S. Which pair of elements has the same number of valence electrons? A. P and S B. P and Q C. Q and R D. Q and S Ans: A 11. Diagram below shows the atomic structure of atom Q. Which of the following is the standard representation of atom of element Q? A. 22 18𝑄 B. 18 22𝑄 C. 40 22𝑄 D. 40 18𝑄 Ans: D 12. Diagram below shows the electron arrangement of R2- ion. How many protons and electrons are found in atom R? Proton Electron A. 8 10 B. 8 8 C. 10 10 D. 12 10 Ans: B 13. Diagram below shows the symbol of atom X. Which of the following is true about the number of particles in the atom? Proton Electron Neutron A. 4 4 5 B. 4 5 4 C. 4 4 9 D. 11 5 9 Ans: A 14. Which of the following particles contains 10 electrons? [Proton number: Na = 11, Ne = 10, Cl = 17, Mg = 12] I. Na II Ne III Cl- IV Mg2+ A. I and II B. I and III C. II and IV D. III and IV Ans: C 15. Diagram below shows the standard atomic representation of four elements. Which of the following pairs of elements has the same number of valence electrons in their atoms? A. E and G B. E and M C. G and J D. J and M Ans: B 16. Which of the following scientists introduced this model? A. Niels Bohr B. John Dalton C. Ernest Rutherford D. J.J. Thomson Ans: D 17. What is the function of cobalt-60? A. Study of plant metabolism. B. Kills cancer cells. C. Estimate fossils’ age. D. Detect leakage in pipes. Ans: B 18. What is the function of carbon-14? A. Treat thyroid disorders. B. Detect liquid wastes. C. Estimate fossils’ age. D. Generate electricity through nuclear power generator. Ans: C 19. Magnesium exists naturally as three isotopes, which are 79% of Mg-24, 10% of Mg-25 and 11% of Mg-26. Calculate the relative atomic mass of magnesium. A. 24.0 B. 24.1 C. 24.2 D. 24.3 Ans: D 20. Which of the following substances will undergo sublimation when heated? I. Ammonium chloride II. Iodine III. Bromine IV. Chlorine A. I and II B. II and III C. III and IV D. II, III and IV Ans: A 21. Which of the following is in liquid state at room temperature? Melting point Boiling point A. -23 77 B. -119 5 C. 50 90 D. 77 100 Ans: A 22. Which of the following are correct about their arrangement at room temperature? Solid Liquid Gas A. Chlorine Bromine Iodine B. Iodine Chlorine Bromine C. Bromine Iodine Chlorine D. Iodine Bromine Chlorine Ans: D 23. What is the relative atomic mass of M(NO3)3 when its relative molecular mass is 213? [RAM: N=14, O=16] A. 27 B. 55 C. 81 D. 151 Ans: A 24. The chemical formula of calcium carbonate is CaCO3. The chemical formula of magnesium nitrate is Mg(NO3)2. What is the chemical formula of magnesium carbonate? A. MgCO B. MgCO3 C. Mg(CO3)2 D. Mg2(CO3) Ans: B 25. Which of the following has the same number of atoms as 1 mol of Carbon? A. 0.5 mol of Magnesium, Mg B. 0.5 mol of bromine gas, Br2 C. 1 mol of sodium chloride, NaCl D. 1 mol of carbon dioxide, CO2 Ans: B 26. What is the molar mass of calcium chloride hexahydrate (CaCl2.6H2O)? [RAM: Ca=40, Cl=35.5, H=1, O=16] A. 93.5 g mol-1 B. 123 g mol-1 C. 129 g mol-1 D. 219 g mol-1 Ans: D 27. The molecular formula of butyl ethanoate is CH3COOC4H9. What is the empirical formula of butyl ethanoate? A. C3H6O B. C3H4O C. C2H4O D. CH3O Ans: A 28. What is the number of total atoms in 1.5 mol of calcium nitrate, Ca(NO3)2? NA=6.02 × 1023 mol-1 A. 9.02 ×1023 atoms B. 1.806 ×1024 atoms C. 2.709 ×1024 atoms D. 9.03 ×1024 atoms Ans: C 29. What is the volume of 26.4 g of carbon dioxide, CO2 at room conditions (24 dm3 mol-1)? A. 11.4 dm3 B. 12.4 dm3 C. 13.4 dm3 D. 14.4 dm3 Ans: D 30. Given that glucose has the empirical formula of CH2O, and its relative molecular mass is 180. What is the molecular formula? A. CH2O B. C2H4O2 C. C3H4O3 D. C6H12O6 Ans: D 31. Which of the following will produce the smallest volume of gas at room conditions (24 dm3 mol-1)? [RAM: H=1, C=12, N=14, O=16, Br=79] A. 24 g of steam, H2O B. 30 g of bromine gas, Br2 C. 35 g of carbon dioxide, CO2 D. 40 g of nitrogen dioxide, NO2 Ans: B 32. A chemist analysed the compound that gives smell to fully ripe bananas. He found that the compound contains 64.42% of carbon, 10.77% hydrogen and 24.61% oxygen. What is the empirical formula of that compound? [RAM: C=12, H=1, O=16] A. C2H6O B. C3.5H7O C. C7H14O2 D. C3H7O Ans: C 33. What is the number of atoms found in 5.1 g of ammonia gas, NH3? [RAM: H=1, N=14] NA=6.02 × 1023 mol-1 A. 1.912 × 1023 atoms B. 5.737 × 1023 atoms C. 6.108 × 1023 atoms D. 7.224 × 1023 atoms Ans: D 34. Calculate the percentage of iron in iron(II) sulphate heptahydrate, FeSO4.7H2O. [RAM: Fe=56, S=32, O=16, H=1] A. 20.14% B. 30.77% C. 54.68% D. 83.52% Ans: A 35. Which of the following will produce the most number of molecules? [RAM: C=12, O=16, H=1, S=32] A. 6 g of CO B. 7 g of CO2 C. 8 of H2O D. 9 g of SO2 Ans: D 36. Which of the following contains 6.02 × 1023 atoms? A. 1 mol of hydrogen B. 1 mol of magnesium C. 1 mol of oxygen D. 1 mol of bromine Ans: B 37. Which of the following contains the same number of atoms as 0.24g of carbon? [RAM: C=12, N=14, O=16, Ne=20, Cl=35.5] A. 0.71 g of chlorine gas B. 0.44 g of carbon dioxide C. 0.20 g of neon D. 0.14 g of nitrogen gas Ans: A 38. 16g of hydrated magnesium sulphate, MgSO4. 𝑥 H2O contains 6.75 g of water of crystallisation. Find the value of 𝑥. [RAM: H=1, O=16, Mg=24, S=32] A. 3 B. 4 C. 5 D. 6 Ans: C 39. Nitrogen is made up of nitrogen-14 and nitrogen-15. Given that the relative atomic mass of nitrogen is 14.007, what is the percentage of the isotope with the lighter mass? A. 0.7% B. 15% C. 29% D. 99.3% Ans: A 40. Combustion of hydrocarbon compounds will produce more sooty flame if the percentage of carbon content by mass is higher. Which of the following hydrocarbon compounds produces the sootiest flame? [RAM: C=12, H=1] A. C5H12 B. C4H10 C. C3H8 D. C3H6 Ans: D