43
When a solid melts and consequently boils, there is
- A. a gradual increase in the average kinetic energy of the particles
- B. a sudden decrease in the kinetic energy of the particles
- C. no change in the average kinetic energy of the particles
- D. a rapid change in the nature of bonding of the components
- E. a change in the size of the fundamental particles
44
Aluminum is above iron in the electrochemical series, yet iron corrodes easily on exposure to air while aluminium does not. This is because aluminium
- A. has a lower density than iron
- B. is a better conductor than iron
- C. does not corrode spontaneously
- D. forms thin layer of inert oxide in moist air
- E. forms amphoteric oxides while iron does not
45
The heat accompanying the reaction represented by the equation H2O (l) → H 2O(g) is described as the heat of
- A. solution
- B. neutralization
- C. vaporization
- D. sublimation
- E. activation
46
The electronic configuration 1s2 22s 22p 63s23p 6 is that of a
- A. noble gas
- B. Group ll element
- C. Group lll element
- D. Group V element
- E. Group VI element
47
A sample of orange juice is suspected to have been contaminated with a yellow dye. Which of the following methods can be used to detect the dye?
- A. Decantation
- B. Chromatography
- C. Distillation
- D. Filtration
- E. Evaporation
48
Which of the following reaction will not take place under normal conditions?
- A. Zn(s) + 2HCl → ZnCI2(aq) + H 2(g)
- B. Fe (s) + H 2SO4(aq) → FeSO4(aq) + H2(g)
- C. Cu (s) + 2HCI (aq) → CuCI 2(aq) + H2(g)
- D. Ca(s) + 2H 2O (1) → Ca(OH)2(g) + H2(g)
- E. 2Na(s) + 2H 2O (1) → 2NaOH(aq) + H2(g)
49
Catalytic hydrogenation of oils results in the production of
- A. soaps
- B. detergents
- C. alkanes
- D. butter
- E. margarine