Chemistry, 2002, JAMB Exam, Exam, Paper 1 | Objectives

Paper Info

Year :

2002

Title :

Chemistry

Exam :

JAMB Exam

Paper 1 | Objectives

1 - 10 of 47 Questions

#	Question	Ans
1.	A compound contains 31.91% potassium, 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound? [K = 39, Cl = 35.5, O = 16] A. KClO₄ B. KClO C. KClO₂ D. KClO₃ Show Content Detailed Solution K- (31.91%), Mole = 31.91/39 =0.8182 Cl-(28.93%), Mole = 28.93/35.5 = 0.815 O-(39.16%), Mole = 39.6/16 = 2.448 K = 0.8182/0.815 = 1 Cl = 0.815/0.815 = 1 O = 2.448/0.815 = 3	D
2.	The formula CH₂ for ethanoic acid is regarded as its A. Molecular formula B. General formula C. Empirical formula D. Structural formula	C
3.	A little quantity of trichloromethane (b.pt 60,^oC) was added to a large quantity of ethanol (b.pt 78,^oC). The most probable boiling point of the resultant mixture is from A. 69 ^oC - 70 ^oC B. 70 ^oC – 74 ^oC C. 82 ^oC – 84 ^oC D. 60 ^oC – 78 ^oC	C
4.	The chromatography separation of ink is based on the ability of the components to A. React with solvent B. React with each other C. Dissolve in each other in the column D. Move at different speeds in the column	D
5.	In the reaction E+F ↔ G+H, the backward reaction is favoured if the concentration of A. F is increased B. E is increased C. E is reduced D. G is reduced	C
6.	What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied? A. 2.01g B. 1.00g C. 4.02g D. 8.04g Show Content Detailed Solution Zn²⁺ + 2e^- → Zn 2F will be liberated 65g of Zn, if 0.65gm of Zn is liberated, the quantity of electricity used X = (0.65/65) * 2 = 0.02F ∴ Hg⁺ + e^- → Hg¹ i.e 1F → 201gm of Hg ∴ 0.02 will liberated Y = (0.02/1) * 201 = 4.02g	C
7.	Which of the following equations show that a reaction is in equilibrium? A. ΔG < O B. ΔG = ΔH – TΔS C. ΔG > O D. ΔG = O	D
8.	PCl_5(g) ↔ PCl_3(g) + Cl_2(g) In the reaction above, a decrease in pressure will A. Decelerate the reaction B. Increase the yield of PCl₃ C. Increase the yield of PCl₅ D. Accelerate the reaction	B
9.	When H2S is passed into a solution of iron (III) chloride, the solution turns A. Pale green B. Pale red C. Brown D. Colourless Show Content Detailed Solution A reaction between Iron (iii) chloride and Hydrogen sulphide leads to the reaction 2FeCl3(aq) + H2S(g) → 2FeCl2(aq) + 2HCl(aq) + S(s) The colour change is from REDDISH BROWN to PALE GREEN.	A
10.	The Arrhenius equation expresses the relationship between the speed of a reaction and its A. Molecular collision B. Heat of reaction C. Catalyst D. Activation energy	D

1.	A compound contains 31.91% potassium, 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound? [K = 39, Cl = 35.5, O = 16] A. KClO₄ B. KClO C. KClO₂ D. KClO₃ Show Content Detailed Solution K- (31.91%), Mole = 31.91/39 =0.8182 Cl-(28.93%), Mole = 28.93/35.5 = 0.815 O-(39.16%), Mole = 39.6/16 = 2.448 K = 0.8182/0.815 = 1 Cl = 0.815/0.815 = 1 O = 2.448/0.815 = 3	D
2.	The formula CH₂ for ethanoic acid is regarded as its A. Molecular formula B. General formula C. Empirical formula D. Structural formula	C
3.	A little quantity of trichloromethane (b.pt 60,^oC) was added to a large quantity of ethanol (b.pt 78,^oC). The most probable boiling point of the resultant mixture is from A. 69 ^oC - 70 ^oC B. 70 ^oC – 74 ^oC C. 82 ^oC – 84 ^oC D. 60 ^oC – 78 ^oC	C
4.	The chromatography separation of ink is based on the ability of the components to A. React with solvent B. React with each other C. Dissolve in each other in the column D. Move at different speeds in the column	D
5.	In the reaction E+F ↔ G+H, the backward reaction is favoured if the concentration of A. F is increased B. E is increased C. E is reduced D. G is reduced	C

6.	What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied? A. 2.01g B. 1.00g C. 4.02g D. 8.04g Show Content Detailed Solution Zn²⁺ + 2e^- → Zn 2F will be liberated 65g of Zn, if 0.65gm of Zn is liberated, the quantity of electricity used X = (0.65/65) * 2 = 0.02F ∴ Hg⁺ + e^- → Hg¹ i.e 1F → 201gm of Hg ∴ 0.02 will liberated Y = (0.02/1) * 201 = 4.02g	C
7.	Which of the following equations show that a reaction is in equilibrium? A. ΔG < O B. ΔG = ΔH – TΔS C. ΔG > O D. ΔG = O	D
8.	PCl_5(g) ↔ PCl_3(g) + Cl_2(g) In the reaction above, a decrease in pressure will A. Decelerate the reaction B. Increase the yield of PCl₃ C. Increase the yield of PCl₅ D. Accelerate the reaction	B
9.	When H2S is passed into a solution of iron (III) chloride, the solution turns A. Pale green B. Pale red C. Brown D. Colourless Show Content Detailed Solution A reaction between Iron (iii) chloride and Hydrogen sulphide leads to the reaction 2FeCl3(aq) + H2S(g) → 2FeCl2(aq) + 2HCl(aq) + S(s) The colour change is from REDDISH BROWN to PALE GREEN.	A
10.	The Arrhenius equation expresses the relationship between the speed of a reaction and its A. Molecular collision B. Heat of reaction C. Catalyst D. Activation energy	D