Year :
1997
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
21 - 30 of 48 Questions
| # | Question | Ans |
|---|---|---|
| 21. |
How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H2 + O2→ 2H2O,∆H = -571.7KJ (H = 1) A. 1.42.9KJ B. 571.7KJ C. 1143.4KJ D. 285.9KJ E. 2286.8KJ |
C |
| 22. |
The position of equilibrium in a reversible reaction is affected by A. particle size of the reactants B. change in concentration of the reactants C. change in size of the reaction vessel D. vigorous stirring of the reaction mixture E. presence of a catalyst |
B |
| 23. |
Separation of mixture of solids by physical methods can be based on differences in the following except A. melting point B. solubility C. particle size D. molar mass E. magnetic property |
D |
| 24. |
Ethene undergoes mainly addition reactions because it is A. a gas B. a hydrocarbon C. unsaturated D. easily polymerized E. a covalent compound |
C |
| 25. |
The reaction between alkanoic acids and alkanols in the presence of a mineral acid is known as A. saponification B. hydrolysis C. polymerization D. esterification E. dehydration |
D |
| 26. |
Which of the following is the relative molecular mass of a compound which has empirical formula CH\(_2\)O? (H = 1; C = 12; O = 16) A. 42 B. 45 C. 126 D. 180 E. 145 Detailed SolutionEmpirical formula = CH\(_2\)O= 12 + (2 x 1) + 16 = 30 Molecular formula = (CH\(_2\)O)\(_n\), where n is a whole number. = 30n \(\therefore\) From the options, only 180 is a multiple of 30. Hence, that is the only likely molecular mass with respect to CH\(_2\)O. |
|
| 27. |
The by-product of the fermentation of sugar to ethanol is A. propane -1,2,3-triol B. ethyl ethanoate C. ethanedioc acid D. propanol E. carbon (lV) oxide |
E |
| 28. |
Alkanes react with the halogens mainly by A. oxidation B. polymerization C. addition D. reduction E. substitution |
E |
| 29. |
Which of the following is used widely in the manufacture of flavours and perfumes? A. Alkanoates B. Alkanones C. Alkanes D. Complex sugars E. Aliphatic compounds |
A |
| 30. |
The use of diamond in abrasives is due ti its A. high melting point B. durability C. lustre D. hardness E. octahedral shape |
D |
| 21. |
How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H2 + O2→ 2H2O,∆H = -571.7KJ (H = 1) A. 1.42.9KJ B. 571.7KJ C. 1143.4KJ D. 285.9KJ E. 2286.8KJ |
C |
| 22. |
The position of equilibrium in a reversible reaction is affected by A. particle size of the reactants B. change in concentration of the reactants C. change in size of the reaction vessel D. vigorous stirring of the reaction mixture E. presence of a catalyst |
B |
| 23. |
Separation of mixture of solids by physical methods can be based on differences in the following except A. melting point B. solubility C. particle size D. molar mass E. magnetic property |
D |
| 24. |
Ethene undergoes mainly addition reactions because it is A. a gas B. a hydrocarbon C. unsaturated D. easily polymerized E. a covalent compound |
C |
| 25. |
The reaction between alkanoic acids and alkanols in the presence of a mineral acid is known as A. saponification B. hydrolysis C. polymerization D. esterification E. dehydration |
D |
| 26. |
Which of the following is the relative molecular mass of a compound which has empirical formula CH\(_2\)O? (H = 1; C = 12; O = 16) A. 42 B. 45 C. 126 D. 180 E. 145 Detailed SolutionEmpirical formula = CH\(_2\)O= 12 + (2 x 1) + 16 = 30 Molecular formula = (CH\(_2\)O)\(_n\), where n is a whole number. = 30n \(\therefore\) From the options, only 180 is a multiple of 30. Hence, that is the only likely molecular mass with respect to CH\(_2\)O. |
|
| 27. |
The by-product of the fermentation of sugar to ethanol is A. propane -1,2,3-triol B. ethyl ethanoate C. ethanedioc acid D. propanol E. carbon (lV) oxide |
E |
| 28. |
Alkanes react with the halogens mainly by A. oxidation B. polymerization C. addition D. reduction E. substitution |
E |
| 29. |
Which of the following is used widely in the manufacture of flavours and perfumes? A. Alkanoates B. Alkanones C. Alkanes D. Complex sugars E. Aliphatic compounds |
A |
| 30. |
The use of diamond in abrasives is due ti its A. high melting point B. durability C. lustre D. hardness E. octahedral shape |
D |