1.00g of mixture of calcium carbonate and calcium oxide liberated 0.33g of carbon dioxide on strong heating. The percentage of calcium oxide in the mixture is? (Ca = 40, C = 12, O = 16)
- A. 5
- B. 15
- C. 25
- D. 35
- E. 50
The i.u.p.A.C name for the compound
- A. 2-chloro-isopentane
- B. 3-chloro-isopentane
- C. 2-chloro-2-methylbutane
- D. 1-chloro-2,2- dimethylpropane
- E. 2-chloro-2-ethylpropane
The solubility curve of a solid X (molecular mass = 160) is as show above. 1,000 cm3 of a saturated solution of X at 80ยฐC is cooled to 40ยฐC . The weight of X crystalized out would be
- A. 10 g
- B. 12 g
- C. 14 g
- D. 16 g
- E. 18 g
60cm3 of hydrogen are sparked with 20cm3 of oxygen at 100ยฐC and 1 atmosphere. The total volume of the residual gases is?
- A. 60 cm3
- B. 10 cm3
- C. 40 cm3
- D. 30 cm3
- E. 70 cm3
The number of grammes of potassium hydroxide in 250cm3 of one molar solution is?
(K = 39, O = 16, H = 1)
- A. 40g
- B. 52g
- C. 100g
- D. 26g
- E. 14g
Brass is an alloy containing copper and?
- A. zinc
- B. tin
- C. aluminium
- D. silver
- E. lead
Which of the following processes NOT lead to a chemical change?
- A. Strirring iron in sulphur (IV) acid
- B. Stirring sodium carbonate in water
- C. Stirring glucose in concentrated sulphur (IV) acid
- D. Mixing sulphur (IV) acid with potassium carbonate
- E. Titrating an acid against base
0.16g of methane when burnt raises the temperature of 100g of water by 40ยฐC. What is the of combustion of methane when if the heat capacity of water is 4.2 Jg-1ยฐC-1?
(CH4 = 16)
- A. 1,160 kJ mol-1
- B. 1,180 kJ mol-1
- C. 1,560 kJ mol-1
- D. 1,600kJ mol-1
- E. 1,680 kJ mol-1
Which of the following is NOT a redox reaction?
- A. 2HNO2 + 2HI โ 2H2O + 2NO + I2
- B. Zn + H2SO4 โ ZnSO4 + H2
- C. Ca(HCO3)2 โ CaCO3 + H2O + CO2
- D. 4FeO + O2 โ 2Fe2O3
- E. 2Na + Cl2 โ 2NaCl
Which of the following combinations of conditions may increase the rate of a chemical reaction?
- A. Decrease in temperature, increase in concentration of the reactants
- B. Increase in temperature, addition of a catalyst, decrease in the surface area of the reactants
- C. Increase in temperature, increase in concentration, addition of a catalyst and increase in the surface area of the reactants
- D. Decrease in temperature concentration and surface area of the reactants
- E. Additionof a catalyst and in the absence of light
What weight of sodium hydroxide is required to make 500 cm3 of 0.2 M solution?
(Na = 23, O = 16, H = 1)
- A. 40 g
- B. 20 g
- C. 10 g
- D. 4 g
- E. 2 g
How many grams of methylacetylene (propyne) CH3 โ C ฮ CH will completely discharge the colour of 8g of bromine?
(Br = 80, C = 12, H = 1)
- A. 0.5
- B. 1.0
- C. 2.0
- D. 3.0
- E. 4.0
Magnesium ribbon was added to each of the following aqueous solution in turn: H2SO4, AgNO3, HNO3, HCl, NH3, HCl, NH3. In which case does the magnesium become covered with a dark precipitate?
- A. H2SO4
- B. AgNO3
- C. HNO3
- D. NH3
- E. HCl
When copper powder is heated with concentrated sulphuric acid, the gas produced is?
- A. hydrogen sulphide
- B. sulphur dioxide
- C. sulphur trioxide
- D. hydrogen pentasulphide
- E. sulphur pentoxide
In the preparation of carbon monoxide by heating ethanedioic acid with concentrated sulphuric acid, the concentrated sulphuric acid act as?
- A. an oxidizing agent
- B. a reducing agent
- C. a dehydrating agent
- D. a reaction medium
- E. a catalyst
A current of 10.0A was passed for 1 hour through a solution of copper (ll) sulphate between the copper electrodes. Which of the following observation would be correct?
(1 Faraday = 96,500 coulombs) (i) 0.186 mole of copper is dissolved from the anode. (ii) 0.372 mole of copper is deposited on the cathode. (iii) the original Cu2+ ion concentration of the solution remains unchanged. (iv) the original Cu2+ ion concentration of the solution decreases.
- A. i and ii
- B. i and iii
- C. i and iv
- D. ii and iii
- E. ii and iv
Which of the following is a neutralization reaction? Addition of
- A. nitric acid to hydrochloric acid
- B. nitric acid to sulphuric acid
- C. nitric acid to distilled water
- D. nitric acid to sodium hydroxide
- E. sodium chloride to distilled water
An element X has two isotopes, \(^{20} _{10}X\) and \(^{22} _{10}X\),
present in the ratio 1:3. The relative atomic mass of X would be?
- A. 20.5
- B. 21.0
- C. 21.5
- D. 22.0
- E. 22.5
When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?
- A. decrease, since only a fraction of the water molecules has changed to vapour
- B. remain constant, because the total number of water molecules has not changed
- C. increase, because the water molecules can now reach every part of the sealed tube
- D. decrease, since water boils under reduced pressure
- E. increase, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity
Which of the following bonds exist in crystalline ammonium chloride (NH4Cl)?
- A. Ionic and covalent
- B. Ionic and co-ordinate
- C. Ionic covalent and co-ordinate
- D. Covalent , co-ordinate and metalllic
- E. Ionic, covalent and metallic
The pressure on 100 cm3 of oxygen gas at 35ยฐC is 750mm of Hg.What would be the volume of the gas if the pressure is increased to 1000mm of Hg without changing the temperature?
- A. 133.3 cm3
- B. 85 cm3
- C. 75 cm3
- D. 65 cm3
- E. 58.3 cm3