Chemistry, 1993, JAMB Exam, Exam, Paper 1 | Objectives

Paper Info

Year :

1993

Title :

Chemistry

Exam :

JAMB Exam

Paper 1 | Objectives

21 - 30 of 49 Questions

#	Question	Ans
21.	The standard enthalpies of formation of CO_2(g), H₂O(g) and CO_(g) in kJ mol^- are -394, -242 and -110 respectively. What is the standard enthalpy change for the reaction CO_(g) + H_2(g)O → CO_2(g) + H_2(g)? A. -42 KJ mol^- B. +42 KJ mol^- C. -262 KJ mol^- D. +262 KJ mol^- Show Content Detailed Solution Standard enthalpy change of a process = ∆H° process = ∆H° _F reactant - D_F° products	A
22.	10g of a solid is in equilibrium with its own vapour. When 1 g of a small amount of solid is added, the vapour pressure? A. remains the same B. drops C. increases by 1% D. increases by 99%	B
23.	NaCI_(s) + H₂SO_4(I) → HCI_(g) + NaHSO_4(s). In the reaction above, H₂SO₄ behaves as? A. a strong acid B. an oxidizing agent C. a good solvent D. a dehydrating agent	A
24.	Which of these gases can be dried with concentrated H2SO4? A. HBr B. H₂S C. NH₃ D. SO₂ Show Content Detailed Solution In the preparation of \(SO_{2}\), we have the resultant reaction from heating the mixture of \(Na_{2}SO_{3}\) and \(HCl\) as: \(Na_{2}SO_{{3}{(aq)}} + 2HCl_{(aq)} \to 2NaCl_{(aq)} + H_{2}O_{(l)} + SO_{{2}{(g)}}\) Passing the gas evolved through conc. \(H_{2}SO_{4}\), we collect \(SO_{2}\) by DOWNWARD DELIVERY, leaving \(NaCl\) in the flask.	D
25.	Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating? A. Silver and trioxonitrate (V) B. Sodium trioxonitrate (V) C. Calcium trioxonitrate (V) D. Lithium trioxonitrate (V)	A
26.	An experiment produces a gaseous mixtures of carbon (IV) oxide and carbon (II) oxide. In order to obtain pure carbon (II) oxide, the gas mixture should be? A. passed over heated copper (II) oxide B. bubbled through concentrated tetraoxosulphate (IV) acid C. bubbled through sodium hydroxide solution D. bubbled through water	C
27.	Which of the following is a property of ionic chlorides? A. They can be decomposed by heat B. They react with aqueous AgNO₃ to give a white precipiate which is soluble in excess ammonia C. They explode when in contact with dry ammonia D. They react with concentrated tetraoxosulphate (IV) acid to give white fumes of chlorine gas	B
28.	When dilute aqueous solutions of lead (II) nitrate and potassium bromide are mixed, a precipitate is observed. The products of this reaction are? A. PbO_(s) + Br^- + KNO₃ B. Br₂ + NO_2(g) + PbBr_2(s) C. PbO_(s) + K⁺_(aq) + Br_(aq) + NO_2(g) D. PbBr_2(s) + K_(aq) + K⁺_(aq) + NO_3(aq)	D
29.	Bronze is an alloy of? A. silver and copper B. silver and gold C. copper and nickle D. copper and zinc E. copper and tin Show Content Detailed Solution Bronze is an alloy of copper and tin.	E
30.	The active reducing agent in the blast furnace for the extraction of iron is? A. carbon B. limestone C. carbon(II)oxide D. calcium oxide	C

21.	The standard enthalpies of formation of CO_2(g), H₂O(g) and CO_(g) in kJ mol^- are -394, -242 and -110 respectively. What is the standard enthalpy change for the reaction CO_(g) + H_2(g)O → CO_2(g) + H_2(g)? A. -42 KJ mol^- B. +42 KJ mol^- C. -262 KJ mol^- D. +262 KJ mol^- Show Content Detailed Solution Standard enthalpy change of a process = ∆H° process = ∆H° _F reactant - D_F° products	A
22.	10g of a solid is in equilibrium with its own vapour. When 1 g of a small amount of solid is added, the vapour pressure? A. remains the same B. drops C. increases by 1% D. increases by 99%	B
23.	NaCI_(s) + H₂SO_4(I) → HCI_(g) + NaHSO_4(s). In the reaction above, H₂SO₄ behaves as? A. a strong acid B. an oxidizing agent C. a good solvent D. a dehydrating agent	A
24.	Which of these gases can be dried with concentrated H2SO4? A. HBr B. H₂S C. NH₃ D. SO₂ Show Content Detailed Solution In the preparation of \(SO_{2}\), we have the resultant reaction from heating the mixture of \(Na_{2}SO_{3}\) and \(HCl\) as: \(Na_{2}SO_{{3}{(aq)}} + 2HCl_{(aq)} \to 2NaCl_{(aq)} + H_{2}O_{(l)} + SO_{{2}{(g)}}\) Passing the gas evolved through conc. \(H_{2}SO_{4}\), we collect \(SO_{2}\) by DOWNWARD DELIVERY, leaving \(NaCl\) in the flask.	D
25.	Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating? A. Silver and trioxonitrate (V) B. Sodium trioxonitrate (V) C. Calcium trioxonitrate (V) D. Lithium trioxonitrate (V)	A

26.	An experiment produces a gaseous mixtures of carbon (IV) oxide and carbon (II) oxide. In order to obtain pure carbon (II) oxide, the gas mixture should be? A. passed over heated copper (II) oxide B. bubbled through concentrated tetraoxosulphate (IV) acid C. bubbled through sodium hydroxide solution D. bubbled through water	C
27.	Which of the following is a property of ionic chlorides? A. They can be decomposed by heat B. They react with aqueous AgNO₃ to give a white precipiate which is soluble in excess ammonia C. They explode when in contact with dry ammonia D. They react with concentrated tetraoxosulphate (IV) acid to give white fumes of chlorine gas	B
28.	When dilute aqueous solutions of lead (II) nitrate and potassium bromide are mixed, a precipitate is observed. The products of this reaction are? A. PbO_(s) + Br^- + KNO₃ B. Br₂ + NO_2(g) + PbBr_2(s) C. PbO_(s) + K⁺_(aq) + Br_(aq) + NO_2(g) D. PbBr_2(s) + K_(aq) + K⁺_(aq) + NO_3(aq)	D
29.	Bronze is an alloy of? A. silver and copper B. silver and gold C. copper and nickle D. copper and zinc E. copper and tin Show Content Detailed Solution Bronze is an alloy of copper and tin.	E
30.	The active reducing agent in the blast furnace for the extraction of iron is? A. carbon B. limestone C. carbon(II)oxide D. calcium oxide	C