Year :
2020
Title :
Chemistry
Exam :
JAMB Exam
Paper 1 | Objectives
21 - 30 of 40 Questions
| # | Question | Ans |
|---|---|---|
| 21. |
A few drop of conc HCL are added to about 10cm\(^3\) of a solution of PH 3.4. The PH of the resulting mixture is? A. less than 3.4 B. greater than 3.4 C. unaltered D. the same as that of the pure water Detailed SolutionThe addition of conc HCL makes the solution more acidic and the solution falls below the original valueThere is an explanation video available below. |
|
| 22. |
Chromatography is used to separate components of mixture which differ in their rates of ? A. diffusion B. migration C. reaction D. sedimentation Detailed SolutionChromatography is a method of separating mixtures by using a moving solvent on filter paper.The rate at which each solute moves up the paper depends on how strongly it is absorbed by the paper, and how soluble it is in the solvent. There is an explanation video available below. |
|
| 23. |
Deliquescent substances are also? A. efflorescent B. anhydrous C. hygroscopic D. insoluble Detailed SolutionDeliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution. Deliquescence occurs when the vapour pressure of the solution that is formed is less than the partial pressure of water vapour in the air. A particular example of hygroscopic behavior is deliquescence which is exhibited by many water-soluble solids, including inorganic salts (e.g., calcium chloride).There is an explanation video available below. |
|
| 24. |
Helium is used in observation of ballons because it is? A. Light and combustible B. light and non-combustible C. heavy and combustible D. heavy and non-combustible Detailed SolutionHelium floats because it is buoyant; its molecules are lighter than the nitrogen and oxygen molecules of our atmosphere and so they rise above itThere is an explanation video available below. |
|
| 25. |
32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in 1dm\(^3\) of water generated 13.0kj of heat. The heat solution is? A. 26.0kj/mol B. 65.0kj/mol C. 130.0kj/mol D. 260.0kj/mol Detailed Solution32g of CUSO\(_4\) liberate 13.0kj of heatMolar mass of CUSO\(_4\) = 160g No. of moles of CUSO\(_4\) = 32g No. of moles = 32(mass) / 160(molar mass) = 0.2 moles i.e 0.2 = 13kj 1 moles = xkj : 65KJ There is an explanation video available below. |
|
| 26. |
A gaseous metallic chloride MCl consists of 20.22% of M by mass. The formula of the chloride is?[ M = 27, Cl = 35.5] A. MCl B. MCl\(_2\) C. MCl\(_3\) D. M\(_2\)Cl\(_6\) Detailed SolutionThe formula of the Chloride = MCl\(_3\)There is an explanation video available below. |
|
| 27. |
What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution? A. 24,125 C B. 48,250 C C. 72,375 C D. 96,500 C Detailed Solution4OH ⇒ 2H\(_2\)O + O\(_2\) + 4e-From the equation: 1 mole of Oxygen requires 4e i.e 1 mole of Oxygen requires 4F, where 1F = 96,500 C [ 4 X 96,500 X 0.125 ] ÷ 1 = 48,250 C There is an explanation video available below. |
|
| 28. |
Which of the following types of bonding does not involve the formation of new substances? A. Metallic B. Covalent C. Co-ordinate D. Electrovalent |
|
| 29. |
An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be? A. Alkene B. Alkanal C. Alkanone D. Alkanoic Acid Detailed Solutionalkanone & alkanal react with HCN to form compounds known as cyanohyderins. They also react with hydroxylamine to form oximes.There is an explanation video available below. |
|
| 30. |
The substance often used for vulcanization of rubber is? A. Chlorine B. Hydrogen peroxide C. Sulphur D. Tetraoxosulphate(vi) acid Detailed SolutionOne of the several uses of sulfur is for the vulcanization of rubber.There is an explanation video available below. |
| 21. |
A few drop of conc HCL are added to about 10cm\(^3\) of a solution of PH 3.4. The PH of the resulting mixture is? A. less than 3.4 B. greater than 3.4 C. unaltered D. the same as that of the pure water Detailed SolutionThe addition of conc HCL makes the solution more acidic and the solution falls below the original valueThere is an explanation video available below. |
|
| 22. |
Chromatography is used to separate components of mixture which differ in their rates of ? A. diffusion B. migration C. reaction D. sedimentation Detailed SolutionChromatography is a method of separating mixtures by using a moving solvent on filter paper.The rate at which each solute moves up the paper depends on how strongly it is absorbed by the paper, and how soluble it is in the solvent. There is an explanation video available below. |
|
| 23. |
Deliquescent substances are also? A. efflorescent B. anhydrous C. hygroscopic D. insoluble Detailed SolutionDeliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution. Deliquescence occurs when the vapour pressure of the solution that is formed is less than the partial pressure of water vapour in the air. A particular example of hygroscopic behavior is deliquescence which is exhibited by many water-soluble solids, including inorganic salts (e.g., calcium chloride).There is an explanation video available below. |
|
| 24. |
Helium is used in observation of ballons because it is? A. Light and combustible B. light and non-combustible C. heavy and combustible D. heavy and non-combustible Detailed SolutionHelium floats because it is buoyant; its molecules are lighter than the nitrogen and oxygen molecules of our atmosphere and so they rise above itThere is an explanation video available below. |
|
| 25. |
32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in 1dm\(^3\) of water generated 13.0kj of heat. The heat solution is? A. 26.0kj/mol B. 65.0kj/mol C. 130.0kj/mol D. 260.0kj/mol Detailed Solution32g of CUSO\(_4\) liberate 13.0kj of heatMolar mass of CUSO\(_4\) = 160g No. of moles of CUSO\(_4\) = 32g No. of moles = 32(mass) / 160(molar mass) = 0.2 moles i.e 0.2 = 13kj 1 moles = xkj : 65KJ There is an explanation video available below. |
| 26. |
A gaseous metallic chloride MCl consists of 20.22% of M by mass. The formula of the chloride is?[ M = 27, Cl = 35.5] A. MCl B. MCl\(_2\) C. MCl\(_3\) D. M\(_2\)Cl\(_6\) Detailed SolutionThe formula of the Chloride = MCl\(_3\)There is an explanation video available below. |
|
| 27. |
What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution? A. 24,125 C B. 48,250 C C. 72,375 C D. 96,500 C Detailed Solution4OH ⇒ 2H\(_2\)O + O\(_2\) + 4e-From the equation: 1 mole of Oxygen requires 4e i.e 1 mole of Oxygen requires 4F, where 1F = 96,500 C [ 4 X 96,500 X 0.125 ] ÷ 1 = 48,250 C There is an explanation video available below. |
|
| 28. |
Which of the following types of bonding does not involve the formation of new substances? A. Metallic B. Covalent C. Co-ordinate D. Electrovalent |
|
| 29. |
An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be? A. Alkene B. Alkanal C. Alkanone D. Alkanoic Acid Detailed Solutionalkanone & alkanal react with HCN to form compounds known as cyanohyderins. They also react with hydroxylamine to form oximes.There is an explanation video available below. |
|
| 30. |
The substance often used for vulcanization of rubber is? A. Chlorine B. Hydrogen peroxide C. Sulphur D. Tetraoxosulphate(vi) acid Detailed SolutionOne of the several uses of sulfur is for the vulcanization of rubber.There is an explanation video available below. |