The idea of planetary electron was that of
- A. Rutherford
- B. Thompson
- C. Bohr
- D. Dalton
The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is
- A. dissolution → dryness → filtration → evaporation
- B. filtration → sublimation → evaporation → dryness
- C. sublimation → dissolution → filtration → evaporation
- D. dissolution → filtration → sublimation → evaporation
A decrease in atomic size and an increase in nuclear charge across a period lead to
- A. an increase in the tendency to lose electron
- B. an increase in chemical reactivity
- C. a decrease in electropositivity
- D. a decrease in covalency in bond formation
The element with the electron configuration 1s22s22p3 is
- A. calcium
- B. chlorine
- C. oxygen
- D. nitrogen
What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g?
- A. 62.5 g
- B. 40.0 g
- C. 6.3 g
- D. 2.5 g
Nuclear fission involves the splitting of a heavy element into two nuclei of
- A. nearly equal masses with a relaese of energy and radiaton
- B. equal masses with a relaese of energy
- C. equal masses with a release of energy and radiation
- D. unequal masses without any relaese of energy
The volume of 2.5 moles of oxygen at s.t.p is
[Molar volume of a gas at s.t.p = 22.4 dm3]
- A. 50.0 dm3
- B. 84.0 dm3
- C. 28.0 dm3
- D. 56.0 dm3
A difference between chemical and physical change is that in a chemical change
- A. oxygen is consumed
- B. heat is supplied
- C. a reversible process oocurs
- D. a new substance is formed
A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a
- A. neutral non-metal
- B. metallic ion
- C. non-metallic ion
- D. neutral metal
When a crystal was added to the clear solution of its salt, the crystal did not dissolve and the solution remained unchange. This showed that the solution was
- A. supersaturated
- B. concentrated
- C. unsaturated
- D. saturated
Water has the ability to dissolve almost all substance because its molecules has a structure with
- A. one positive end and one neutral end
- B. one positive end and one negative end
- C. two negative ends
- D. two positive ends
Which of the following results in the fall of acid rain?
- A. Oxides of lead
- B. Particulate matter
- C. Oxides of sulphur
- D. Gaseous hydrocarbon
When 50cm2 of a saturated solution of sugar of molar mass 342 g at 40oC was evaporated to dryness, 34.2g of dry solid was obtained. The solubility of sugar at 40oC is
- A. 2.0 mol dm-3
- B. 3.5 mol dm-3
- C. 7.0 mol dm-3
- D. 10.0 mol dm-3
The products of the combustion of candle wax are?
- A. hydrogen and water
- B. oxygen and water
- C. carbon (IV) oxide and water
- D. carbon (II) oxide and water
An emulsion may be produced by shaking a detergent solution with
- A. palm wine
- B. ethanoic acid
- C. palm oil
- D. water
One mole of a hydrocarbon contains 36g of carbon and its vapour density is 20. The structure of the hydrocarbon is
- A. CH3C ≡ CH
- B. CH3CH = CH2
- C. CH3CH2C ≡ CH
- D. CH3CH2 CH3
CH3 – CH2 – C≡CH
The hybridization in the compound above is
- A. Sp2
- B. sp
- C. sp3 and sp2
- D. sp3 and sp
Which of the following has an isomer?
- A. C6H6
- B. C2H6
- C. C4H10
- D. C2H4
An example of aliphatic unsaturated hydrocarbon is
- A. pentane
- B. butanol
- C. propene
- D. benzene
Nigerian crude oil is described as light crude because of its
- A. low sulphur content
- B. high natural gas content
- C. high octane number
- D. low aliphatic-hydrocarbon content
The gas obtained as a product of anaerobic action on organic matter buried in the earth is?
- A. ethene
- B. methane
- C. carbon (IV) oxide
- D. nitrogen (IV) oxide