Year :
1978
Title :
Chemistry
Exam :
JAMB Exam
Paper 1 | Objectives
1 - 10 of 48 Questions
| # | Question | Ans |
|---|---|---|
| 1. |
Zinc Oxide is a A. Basic Oxide B. Acidic Oxide C. Amphoteric Oxide D. Neutral Oxide E. Reactive Oxide Detailed SolutionZinc oxide is an amphoteric oxide.- It will dissolve in both acids and alkalis |
|
| 2. |
When sodium chloride and metallic sodium are each dissolved in water A. both processes are exothermic B. both processes are endothermic C. the dissolution of metallic sodium is endothermic D. the dissolution of metallic sodium is exothermic E. the dissolution of sodium chloride is explosive Detailed SolutionWhen small quantities of sodium metal is added to water, there is an exothermic reaction, and they react to form sodium hydroxide and hydrogen. |
|
| 3. |
The periodic classification of elements is an arrangement of the elements in order of their A. Atomic Weights B. Isotopic Weights C. Molecular Weights D. Atomic Numbers E. Atomic Masses |
D |
| 4. |
In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid? A. 5cm3 B. 10cm3 C. 20cm3 D. 25cm3 E. 50cm3 Detailed Solution\(2NaOH + H_{2}SO_{4} = Na_{2}SO_{4} + 2H_{2}O\)V x 0.5M = 2(10 x 1.25) 0.5V = 2 x 12.5 0.5V = 25 V = \(\frac{25}{0.5}\) = \(50cm^{3}\) |
|
| 5. |
A small quantity of solid ammonium chloride (NH4Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone A. distillation B. sublimation C. precipitation D. evaporation E. decomposition |
B |
| 6. |
Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore, A. P will form an electrovalent bond with R B. Q will form a covalent bond with S C. R will form an electrovalent bond with S D. Q will form an electrovalent bond with S E. Q will form a covalent bond with R Detailed SolutionPQ R S Given the above is the electronic arrangement of PQRS elements, Q will form an electrovalent bond with S Further explanation was provided by our student by name (Odebiyi Dare D-cent) via our facebook page. Thus he says: without argument, D is the answer cos electrovalent involves the transfer of electron. Alreadily, Q is 11 with elect configuratn of 2,8,1, i.e havin 1 valency electron whch is ready to be loss by that atom of element Q, also, S is 17, with ele cnfi |
|
| 7. |
An element X forms the following compounds with chlorine; XCl4, XCl3, XCl2. This illustrates the A. law of multiple proportions B. law of chemical proportions C. law of simple proportions D. law of conservation of mass E. law of definite proportions |
A |
| 8. |
The oxidation state of chlorine in potassium chlorate is? A. +1 B. +2 C. +3 D. +5 E. +7 Detailed Solution- potassium chlorate --> KClO\(_3\)valencies of K = +1, O = -2. : (+1) + Cl + ( -2 X 3 atoms ) = 0 Cl + 1 - 6 = 0 Cl = 5 ∴ The oxidation state of chlorine in potassium chlorate is +5 |
|
| 9. |
When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are? A. nitrogen and carbondioxide B. the rare gases C. nitrogen and oxygen D. nitrogen and the rare gases E. nitrogen, carbondioxide and the rare gases Detailed Solution- Alkaline solutions of pyrogallol absorb oxygen efficiently.- Quicklime have a strong chemical affinity to absorb water. - At room temperature, Calcium oxide (CaO) will spontaneously absorb carbon dioxide from the atmosphere. |
|
| 10. |
When heat is absorbed during a chemical reaction, the reaction is said to be A. thermodynamic B. exothermic C. isothermal D. endothermic E. thermostatic |
D |
| 1. |
Zinc Oxide is a A. Basic Oxide B. Acidic Oxide C. Amphoteric Oxide D. Neutral Oxide E. Reactive Oxide Detailed SolutionZinc oxide is an amphoteric oxide.- It will dissolve in both acids and alkalis |
|
| 2. |
When sodium chloride and metallic sodium are each dissolved in water A. both processes are exothermic B. both processes are endothermic C. the dissolution of metallic sodium is endothermic D. the dissolution of metallic sodium is exothermic E. the dissolution of sodium chloride is explosive Detailed SolutionWhen small quantities of sodium metal is added to water, there is an exothermic reaction, and they react to form sodium hydroxide and hydrogen. |
|
| 3. |
The periodic classification of elements is an arrangement of the elements in order of their A. Atomic Weights B. Isotopic Weights C. Molecular Weights D. Atomic Numbers E. Atomic Masses |
D |
| 4. |
In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid? A. 5cm3 B. 10cm3 C. 20cm3 D. 25cm3 E. 50cm3 Detailed Solution\(2NaOH + H_{2}SO_{4} = Na_{2}SO_{4} + 2H_{2}O\)V x 0.5M = 2(10 x 1.25) 0.5V = 2 x 12.5 0.5V = 25 V = \(\frac{25}{0.5}\) = \(50cm^{3}\) |
|
| 5. |
A small quantity of solid ammonium chloride (NH4Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone A. distillation B. sublimation C. precipitation D. evaporation E. decomposition |
B |
| 6. |
Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore, A. P will form an electrovalent bond with R B. Q will form a covalent bond with S C. R will form an electrovalent bond with S D. Q will form an electrovalent bond with S E. Q will form a covalent bond with R Detailed SolutionPQ R S Given the above is the electronic arrangement of PQRS elements, Q will form an electrovalent bond with S Further explanation was provided by our student by name (Odebiyi Dare D-cent) via our facebook page. Thus he says: without argument, D is the answer cos electrovalent involves the transfer of electron. Alreadily, Q is 11 with elect configuratn of 2,8,1, i.e havin 1 valency electron whch is ready to be loss by that atom of element Q, also, S is 17, with ele cnfi |
|
| 7. |
An element X forms the following compounds with chlorine; XCl4, XCl3, XCl2. This illustrates the A. law of multiple proportions B. law of chemical proportions C. law of simple proportions D. law of conservation of mass E. law of definite proportions |
A |
| 8. |
The oxidation state of chlorine in potassium chlorate is? A. +1 B. +2 C. +3 D. +5 E. +7 Detailed Solution- potassium chlorate --> KClO\(_3\)valencies of K = +1, O = -2. : (+1) + Cl + ( -2 X 3 atoms ) = 0 Cl + 1 - 6 = 0 Cl = 5 ∴ The oxidation state of chlorine in potassium chlorate is +5 |
|
| 9. |
When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are? A. nitrogen and carbondioxide B. the rare gases C. nitrogen and oxygen D. nitrogen and the rare gases E. nitrogen, carbondioxide and the rare gases Detailed Solution- Alkaline solutions of pyrogallol absorb oxygen efficiently.- Quicklime have a strong chemical affinity to absorb water. - At room temperature, Calcium oxide (CaO) will spontaneously absorb carbon dioxide from the atmosphere. |
|
| 10. |
When heat is absorbed during a chemical reaction, the reaction is said to be A. thermodynamic B. exothermic C. isothermal D. endothermic E. thermostatic |
D |