Chemistry Past Questions And Answers
The abnormally high boiling point of water is primarily due to
- A) ionic bonding
- B) covalent bonding
- C) dative bonding
- D) hydrogen bonding
The high solubility of ethanol in water is due to?
- A. its low boiling point.
- B. its low freezing point.
- C. its covalent nature
- D. hydrogen bonding
An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?
- A. C2H5OH
- B. C3H4
- C. C6H6
- D. CH3COOH
Ethanol reacts with concentrated tetraoxosulphate (V) acid at a temperature above 170 oC to form
- A) ethanone
- B) ethene
- C) ethyne
- D) ethanal
Which of the following roles does sodium chloride play in soap preparation? It
- A) reacts with glycerol
- B) purifies the soap
- C) accelerates the decomposition of the fat and oil
- D) separates the soap from the glycerol
A common characteristic between zinc and the other transition elements is the ability to
- A) have variable oxidation states
- B) from complex ions
- C) act as a catalyst
- D) from coloured ions
Chemical reactions occurs when the colliding reactants have energy that is
- A. less than the activation energy
- B. greater than the activation energy
- C. greater than the energy of the product
- D. less than the energy of effective collision
Consider the reaction represented by the following equation: N2(g) + 3H2(g) ⇌ 2NH3(g); ΔHÏ´ = -xkJ mol-1. Which of the following conditions would increase the yield of NH3?
- A. Addition of iron catalyst
- B. Increase in the temperature of the system
- C. Increase in the volume occupied by reactants
- D. Increase in the total pressure of the system
Consider the reaction represented by the following equation: N2(g) + 3H2(g) ⇌ 2NH3(g); ΔH = - 92kJ/mol. Finely divided iron is used as catalyst in the reaction in order to
- A. lower the value of ΔH
- B. increase the time for attainment of equilibrium
- C. shorten the time for attainment of equilibrium
- D. decrease the yield of ammonia
(a) (i)Name the class of oxides to which copper (II) oxide belongs.
(ii) Give the reason why copper (II) oxide increases in mass on exposure to the atmosphere
(iii) Write an equation to show the action of dilute hydrochloric acid on copper (II) oxide.
(b) List two methods of removing total hardness from water.
View Discussion (0)WAEC 1996 THEORY