Chemistry Preliminary Quiz


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1. The following schematic diagram represents the fractional distillation of crude oil (crude petroleum) in industry. The letters A to E denote different products obtained from the distillation. Which of the fractions A to E has the lowest boiling point range?

2. Which one of the substances listed below is not an element?
3. What is the change in oxidation number (oxidation state, valency) of Manganese in the reaction represented by the equation below?

MnO2 + 4 HCl → MnCl2 + Cl2 + 2 H2O
4. Tick the statements which are true
5. Substances which are liquid at room temperature include:
6. Which of the following does not lead to an increase in the nitrogen content of soil?
7. The process whereby high-molecular hydrocarbons are converted into low-molecular hydrocarbons is called:
8. The ability to conduct electricity readily is a property of...
9. How is the presence of ions in an aqueous solution most directly detected?
10. The main component of paper is...
11. A 50 mL sample of an aqueous sodium chloride solution containing 8 g per 100 mL of solution is concentrated to half its original volume. What is the concentration of the new solution (in g / 100 mL)?
g / 100 mL
12. The relative atomic mass of Carbon (C) is approximately 12 amu. Roughly, how many Carbon atoms are there in 6 g of Carbon?
13. What is the minimum weight of sodium chloride (NaCl) that is needed to prepare 7.1 g of chlorine?
Relative atomic masses:
Na: 23
Cl: 35.5
14. Tick the statements which are true
15. The graph below shows the solubilities (in g solute/100g water) of sodium nitrate and sodium chloride at different temperatures. Interpret the graph to answer the following question: 100g of sodium nitrate and 100g of sodium chloride are added to 100cm3 of water at 60 °C. The mixture is stirred until no more solid dissolves. It is then filtered, keeping the temperature at 60 °C. What is the residue left on the filter paper?
16. What salt is produced when calcium carbonate is reacted with hydrochloric acid?
17. Amino acids always contain these elements:
18. According to the chemical reactivity series, metals can displace other metals from their solutions.

Which of the following metals will displace copper from its solution?

Gold - Iron - Magnesium - Silver - Zinc
19. An aqueous solution of sodium iodide is electrolysed with platinum electrodes. What is the main product at the negative electrode (cathode)?
20. Correct statements about the material called PVC include:
21. The two non-metals among the following elements are:
22. For the following processes labelled 1 - 5, choose the answer which matches the process to the most appropriate method of separation:
  1. Separating pure iodine from a sample of impure iodine
  2. Separating a dye from a solution of dyes
  3. Separating ethanol from a sample of ethanol in water
  4. Separating sand from a sand/salt mixture
  5. Separating water from a sample of ink
23. When marble pieces are added to hydrochloric acid, the following reaction takes place:

CaCO3(s) + HCl(aq) → CaCl2 + H2O(l) + CO2(g)

Which of the following actions would increase the rate of formation of carbon dioxide?
24. Compounds that have high melthing points, conduct electricity in the molten phase and usually are soluble in water, are
25. From the list, select the gases that can be collected using the apparatus shown in the diagram.
26. Oxides which produce alkaline solutions when mixed with water include:
27. Calculate how many moles of ethanoic acid (CH3COOH, relative molecular mass of 60) may be produced by oxidation of 92 g of ethanol (CH3CH2OH, relative molecular mass of 46).
28. The reaction between Zinc (Zn) and hydrochloric acid (HCl) produces:
29. Match the following definitions labelled 1 - 5 with the correct words below:
  1. _____: The flow or movement of electrons through a conductor.
  2. _____: The electrode at which reduction occurs in a galvanic cell.
  3. _____: The electrode at which oxidation occurs in a galvanic cell.
  4. _____: A substance which conducts electricy in aqueous solution.
  5. _____: The process by which an electric current produces a chemical change.
30. Which of the following would yield the greatest amount of useful energy: