Chemistry, 2018, JAMB Exam, Exam, Paper 1 | Objectives

Paper Info

Year :

2018

Title :

Chemistry

Exam :

JAMB Exam

Paper 1 | Objectives

61 - 70 of 87 Questions

#	Question	Ans
61.	The collision theory explains reaction rates in terms of A. size of the product B. frequency of collision of the reactants C. size of reactant D. frequency of collision of the products Show Content Detailed Solution Collision theory is the theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another. There is an explanation video available below.	B
62.	The presence of ammonia gas in a desiccator can exclusively be removed by A. phosphorus (V) oxide B. fused calcium chloride C. calcium oxide D. concentrated tetraoxosulphate (VI) acid Show Content Detailed Solution Ammonia gas can be removed from a dessicator by adding a conc. H2SO4 so as to neutralize it since ammonia gas is basic. There is an explanation video available below.	D
63.	Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because A. it is insoluble in either dilute or concentrated trioxonitrate (V) acid B. it is lower than hydrogen in the electrochemical series C. the reaction with trioxonitrate (V) acid has a light activation energy D. an insoluble oxide is formed on its surface which renders it passive Show Content Detailed Solution Aluminium doesn’t react with either dilute or concentrated trioxonitrate (V) acid because an insoluble oxide is formed on its surface which renders it passive. It will depend on the concentration of the nitric acid used…. Although aluminium reacts with dilute nitric acid to produce aluminium nitrate and hydrogen gas, concentrated (>60%) nitric acid is such a powerful oxidising agent that it instantly causes a thin layer of aluminium oxide to coat the surface of the aluminium There is an explanation video available below.	D
64.	Which of these sources of water may likely contain the least concentration of Ca\(^{2+}\) and Mg\(^{2+}\)? A. Spring water B. River water C. Tap water D. Sea water Show Content Detailed Solution Tap water contains less Ca\(^{2+}\) and Mg\(^{2+}\) There is an explanation video available below.	A
65.	The conductivity of an acid solution depends on the A. amount of ions present and their mobilities B. mobilities of the ions present C. amount of ions present D. temperature of the solution Show Content Detailed Solution The conductivity of a solution depends on the number of charge carriers (the concentrations of the ions), the mobility of the charge carriers and their charge. Theoretically, conductivity should increase in direct proportion to concentration. There is an explanation video available below.	A
66.	Which of the following metals cannot replace hydrogen from water or steam? A. Sodium B. Magnesium C. Iron D. Copper Show Content Detailed Solution Metals above hydrogen in the activity series can displace or replace hydrogen present in water (H\(_2\)O) example of such metals are Ca, K, Na etc. But the metals below hydrogen in the activity series cannot replace hydrogen in the activity series example of such metals are Cu, Hg. There is an explanation video available below.	D
67.	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 Show Content Detailed Solution P 6 = 2, 4 Q 11 = 2, 8, 1 R 15 = 2, 8, 5 S 17 = 2, 8, 7 Given the above is the electronic arrangement of PQRS elements, Q will form an electrovalent bond with S. Without argument, D is the answer because electrovalency involves the transfer of electron. Already, Q is 11 with electronic configuration of 2, 8, 1, i.e. having 1 valence electron which is ready to be lost by the atom of element Q, also, S is 17, with electronic configuration of 2, 8, 7. There the 7 valence electron of S attracts that only 1 electron to attain a stable octet structure. There is an explanation video available below.	D
68.	During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment A. the litmus turns blue but no gas is evolved B. the litmus turns blue and oxygen is evolved C. the litmus turns blue and hydrogen is evolved D. the litmus turns red and oxygen is evolved Show Content Detailed Solution During the electrolysis of copper using platinum electrode, Cu and H migrate to the cathode while,SO\(_4\) and OH migrate to the anode.CU is then discharged preferentially at the cathode, acquiring two electrons and is deposited as metallic copper, while OH is discharged preferentially at the anode and deposited as gaseous oxygen, then the SO\(_4\) and H still in the solution react, thereby making d solution acidic and then changing the litmus paper red which is the test for acids. There is an explanation video available below.	D
69.	The derivative of benzene that can be used in making explosives is A. aniline B. xylene C. phenol D. toluene Show Content Detailed Solution Yes, Toluene is used in making explosives, based on information from the textbook "New School Chemistry", pg 541. Phenol is used as a starting material to makes explosive materials such as picric acid. Picric acid is one of the most acidic phenol. Like other strongly nitrated organic compounds, picric acid is an explosive. Toluene, however, is used to produce a stronger explosive material called TriNitroToluene (TNT). Therefore Toluene is the most appropriate answer for this question but in situations where you don't find Toluene in the options provided, then Phenol makes a viable answer. There is an explanation video available below	D
70.	In electrovalency, the oxidation number of the participating metal is always A. decreasing B. increasing C. constant D. neutral Show Content Detailed Solution In electro-valency the oxidation number of the participating metal remains constant There is an explanation video available below.	C

61.	The collision theory explains reaction rates in terms of A. size of the product B. frequency of collision of the reactants C. size of reactant D. frequency of collision of the products Show Content Detailed Solution Collision theory is the theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another. There is an explanation video available below.	B
62.	The presence of ammonia gas in a desiccator can exclusively be removed by A. phosphorus (V) oxide B. fused calcium chloride C. calcium oxide D. concentrated tetraoxosulphate (VI) acid Show Content Detailed Solution Ammonia gas can be removed from a dessicator by adding a conc. H2SO4 so as to neutralize it since ammonia gas is basic. There is an explanation video available below.	D
63.	Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because A. it is insoluble in either dilute or concentrated trioxonitrate (V) acid B. it is lower than hydrogen in the electrochemical series C. the reaction with trioxonitrate (V) acid has a light activation energy D. an insoluble oxide is formed on its surface which renders it passive Show Content Detailed Solution Aluminium doesn’t react with either dilute or concentrated trioxonitrate (V) acid because an insoluble oxide is formed on its surface which renders it passive. It will depend on the concentration of the nitric acid used…. Although aluminium reacts with dilute nitric acid to produce aluminium nitrate and hydrogen gas, concentrated (>60%) nitric acid is such a powerful oxidising agent that it instantly causes a thin layer of aluminium oxide to coat the surface of the aluminium There is an explanation video available below.	D
64.	Which of these sources of water may likely contain the least concentration of Ca\(^{2+}\) and Mg\(^{2+}\)? A. Spring water B. River water C. Tap water D. Sea water Show Content Detailed Solution Tap water contains less Ca\(^{2+}\) and Mg\(^{2+}\) There is an explanation video available below.	A
65.	The conductivity of an acid solution depends on the A. amount of ions present and their mobilities B. mobilities of the ions present C. amount of ions present D. temperature of the solution Show Content Detailed Solution The conductivity of a solution depends on the number of charge carriers (the concentrations of the ions), the mobility of the charge carriers and their charge. Theoretically, conductivity should increase in direct proportion to concentration. There is an explanation video available below.	A

66.	Which of the following metals cannot replace hydrogen from water or steam? A. Sodium B. Magnesium C. Iron D. Copper Show Content Detailed Solution Metals above hydrogen in the activity series can displace or replace hydrogen present in water (H\(_2\)O) example of such metals are Ca, K, Na etc. But the metals below hydrogen in the activity series cannot replace hydrogen in the activity series example of such metals are Cu, Hg. There is an explanation video available below.	D
67.	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 Show Content Detailed Solution P 6 = 2, 4 Q 11 = 2, 8, 1 R 15 = 2, 8, 5 S 17 = 2, 8, 7 Given the above is the electronic arrangement of PQRS elements, Q will form an electrovalent bond with S. Without argument, D is the answer because electrovalency involves the transfer of electron. Already, Q is 11 with electronic configuration of 2, 8, 1, i.e. having 1 valence electron which is ready to be lost by the atom of element Q, also, S is 17, with electronic configuration of 2, 8, 7. There the 7 valence electron of S attracts that only 1 electron to attain a stable octet structure. There is an explanation video available below.	D
68.	During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment A. the litmus turns blue but no gas is evolved B. the litmus turns blue and oxygen is evolved C. the litmus turns blue and hydrogen is evolved D. the litmus turns red and oxygen is evolved Show Content Detailed Solution During the electrolysis of copper using platinum electrode, Cu and H migrate to the cathode while,SO\(_4\) and OH migrate to the anode.CU is then discharged preferentially at the cathode, acquiring two electrons and is deposited as metallic copper, while OH is discharged preferentially at the anode and deposited as gaseous oxygen, then the SO\(_4\) and H still in the solution react, thereby making d solution acidic and then changing the litmus paper red which is the test for acids. There is an explanation video available below.	D
69.	The derivative of benzene that can be used in making explosives is A. aniline B. xylene C. phenol D. toluene Show Content Detailed Solution Yes, Toluene is used in making explosives, based on information from the textbook "New School Chemistry", pg 541. Phenol is used as a starting material to makes explosive materials such as picric acid. Picric acid is one of the most acidic phenol. Like other strongly nitrated organic compounds, picric acid is an explosive. Toluene, however, is used to produce a stronger explosive material called TriNitroToluene (TNT). Therefore Toluene is the most appropriate answer for this question but in situations where you don't find Toluene in the options provided, then Phenol makes a viable answer. There is an explanation video available below	D
70.	In electrovalency, the oxidation number of the participating metal is always A. decreasing B. increasing C. constant D. neutral Show Content Detailed Solution In electro-valency the oxidation number of the participating metal remains constant There is an explanation video available below.	C

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