A mixture contains 20cm3 of hydrogen, 35cm3 of oxygen, 15cm3 of carbon monoxide and 10cm3 of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture?
- A. 0.02
- B. 0.16
- C. 0.20
- D. 0.25
- E. 20
The general formula of an alkyl halide (which represent the halide) is?
- A. CnH2n - 2X
- B. CnH2n + 1X
- C. CnH2n + 2X
- D. CnH2nX
- E. CnH2n - 1
An efflorescent compound is a substance that?
- A. absorbs water froom the air without dissolving in it
- B. is capable of giving off coloured luminosity
- C. gives out water to the atmosphere
- D. absorbs water from the air and dissolves in it
- E. gives out its water of crystallization on heating
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
- A. calcium sulphate
- B. calcium carbonate
- C. calcium hydrogen carbonate
- D. calcium hydroxide
- E. magnesium sulphate
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
- A. All the nitrate will decompose to their respective metals
- B. The nitrates of calcium and potassium will decomposes to their nitrites
- C. Only copper nitrate decomposes to the metal
- D. Only the nitrates of zinc and copper will decompose to their oxides
- E. The nitrates of calcium, zinc and copper decompose to their oxides
4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
- A. There were more aluminium atoms in Q than P
- B. The heat given off in retarded the reaction
- C. Q generated more pressure than P during the reaction
- D. P generated more pressure than Q
- E. Q has a greater surface area for the reaction than P
If one mole of aluminium contains 6 x 1023 atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)
- A. 1.0 x 1021
- B. 6.6 x 1021
- C. 2.0 x 1022
- D. 1.0 x 1022
- E. 5.4 x 1023
Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series?
- A. Copper
- B. Iron
- C. Lead
- D. Potassium
- E. Zinc
When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?
- A. both gases change the colour of the solution from yellow to colourless
- B. both gases causes sulphur to be deposited
- C. only hydrogen sulphide decolourizes the solution
- D. only sulphur dioxide deposits sulphur
- E. only hydrogen sulphide deposits sulphur
Which of the following compounds and elements would sublime on exposure to the atmosphere?
- A. Ice
- B. Sulphur
- C. Phosphurous
- D. Iodine
- E. Potassium iodie
What mass of sodium carbonate solution is in 500 cm3 of 0.1 molar sodium carbonate solution?
(Na = 23, C = 12, O = 16)
- A. 10.6 g
- B. 5.3 g
- C. 500 g
- D. 10 g
- E. 20 g
Pure sulfuric acid is a liquid of 1.84 density. What volume of it would be required to prepare 250 cm3 of 2.0 M solution?
(H = 1, S = 32, O = 16)
- A. 2.00
- B. 2.66
- C. 3.00
- D. 3.66
- E. 4.00
In the extraction of iron, which of the following reactions does NOT take place in the blast furnace?
- A. CO2 + C → 2CO
- B. 2Fe2O3 + 3C → 4Fe + 3CO2
- C. Fe2O3 + 3C → 2Fe + 3CO2
- D. CaCO3 → CaO + CO2
- E. CaO + SiO2 → CaSiO3
5cm3 of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?
(Na = 23, Cl = 35.5)
- A. 5.00 mole dm3
- B. 5.67 mole dm3
- C. 6.00 mole dm3
- D. 6.67 mole dm3
- E. 7.00 mole dm3
The electronic configuration of elements X and Y are X = 2, 8, 6; Y = 2, 8, 7. The bond in the compound formed by X and Y is expected to be?
- A. ionic
- B. covalent
- C. dative covalent
- D. metallic
- E. none of the above
Which of the following is NOT a true statement of the kinetic Theory of Gases?
- A. The molecules move at random
- B. The size of molecules is negligble as compared with the volume of gas
- C. The molecular collisions are perfectly elastic
- D. Every molecule has the same kinetic energy at a particular temperature
- E. The average kinetic energy is proportional to the absolute temperature of the gas
The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?
- A. Na2SO4 + SO2 + O2 + H2O
- B. Na2SO3 + SO3 + O2 + H2O
- C. Na2SO4 + SO2 + S + H2O
- D. Na2SO4 + SO3 + S + H2O
- E. Na2SO4 + SO2 + H2O only
The following compounds are given with their corresponding boiling points.
Compound Boiling Point
i……………………………14°C
ii…………………………..24°C
iii…………………………..0°C
iv…………………………..120°C
V……………………………-2°C
From the above information, indicate which of the following is correct?
- A. All the compounds are gaseous at 20 °C
- B. One of the compounds is gaseous at 20 °C
- C. Two of the compounds are gaseous at 20 °C
- D. Three of the compounds are gaseous at 20 °C
- E. None of the compounds is gaseous at 20 °C
If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?
- A. 48,000
- B. 96,000
- C. 192,000
- D. 384,000
- E. 576,000
28.8 cm3 of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?
- A. 17.4 cm3
- B. 14.7 cm3
- C. 27.3 cm3
- D. 31.7 cm3
Which of the following statements about phosphorus is NOT correct?
- A. Phosphorus is a solid mineral
- B. Phosphorus is obtained by oxidation reaction of phosphate
- C. Phosphorus exists in two allotropic forms
- D. Both forms of phosphorus are interconvertible
- E. Yellow phosporus ignites when rubbed on a rough surface