Chemistry Past Questions And Answers
141
Alkenes and _______ are compounds that contain a multiple bond each
- A) Alkanes
- B) Benzene
- C) Alkynes
- D) Benzaldehyde
142
For iodine crystals to sublime on heating, the molecules must acquire energy that is?
- A. less than the forces odf attraction in the solid
- B. equal to the forces of attraction in th solid
- C. necessary to melt the solid
- D. greater than the forces of attraction in both the solid and the liquid phases
143
The reddish-brown rust on iron roofing sheets consists of
- A. Fe3+(H2O)6
- B. FeO.H2O
- C. Fe2O2.3H2O
- D. Fe2O2.2H2O
144
Ammonia is very soluble in water because it is a /an molecule
- A) non-polar
- B) polar
- C) reactive
- D) basic
145
Gas molecules are said to be perfectly elastic because
- A. they collide without loss of energy
- B. they move about in straight lines
- C. the distances between them are negligible
- D. the volume occupied by them is negligible
146
An effect of thermal pollution on water bodies is that the
- A) volume of water reduces
- B) volume of chemical waste increase
- C) level of oxides of nitrogen increase
- D) level of oxygen reduces
147
The process of seeding during the extraction of aluminium involves the addition of pure AI(OH)3 crystals in order to
- A. lower the temperature
- B. increase the concentration
- C. facilitate the precipitation of solid
- D. reduce the viscosity of the solution
148
Transition metals possess variable oxidation states because they have
- A. Electrons in the d orbitals
- B. Electron in the s orbitals
- C. A variable number of electrons in the p orbitals
- D. Partially filled p orbitals
149
Alkynes readily undergo addition reactions with which of the following?
- A. Water (H2O)
- B. Oxygen gas (O2)
- C. Hydrogen gas (H2)
- D. Chlorine gas (Cl2)
150
Glucose gives a brick-red precipitate with Fehling's solution because it is
- A. carbohydrate
- B. an alkanoate
- C. a reducing sugar
- D. a non-electrolyte