Year :
2019
Title :
Chemistry
Exam :
JAMB Exam
Paper 1 | Objectives
41 - 50 of 80 Questions
| # | Question | Ans |
|---|---|---|
| 41. |
Which of the following is a physical change? A. Exposing white phosphorus to air B. Burning kerosene C. Dissolving calcium in water D. Freezing ice cream |
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| 42. |
In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid? A. 25cm\(^3\) B. 10cm\(^3\) C. 20cm\(^3\) D. 50cm\(^3\) Detailed SolutionEquation of reaction : 2NaOH + H\(_2\)SO\(_4\) → Na\(_2\)SO\(_4\) + 2H\(_2\)OConcentration of a base, CB = 0.5M Volume of acid, V\(_A\) = 10cm\(^3\) Concentration of an acid, C\(_A\) = 1.25M Volume of base, V\(_B\) = ? Recall: \(\frac{C_A V_A}{C_B V_B} = \frac{n_A}{n_B}\) ... (1) N.B: From the equation, \(\frac{n_A}{n_B} = \frac{1}{2}\) From (1) \(\frac{1.25 \times 10}{0.5 \times V_B} = \frac{1}{2}\) \(\frac{12.5}{0.5V_B} = \frac{1}{2}\) 25 = 0.5V\(_B\) VB = 50.0 cm\(^3\) There is an explanation video available below.&l |
|
| 43. |
Sulphur exists in six forms in the solid state. This property is known as A. Isomerism B. Allotropy C. Isotopy D. Isomorphism |
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| 44. |
In the reaction: A. Adding a suitable catalyst B. Increasing the concentration of P C. Increasing the temperature D. Decreasing the temperature |
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| 45. |
A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula. A. C\(_3\)H\(_6\)O\(_3\) B. C\(_6\)H\(_6\)O\(_3\) C. C\(_6\)H\(_{12}\)O\(_6\) D. CH\(_2\)O |
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| 46. |
The IUPAC nomenclature of the compound A. 3,4- dimethylhexane B. 2,3- dimethyl pentane C. 2- ethyl hexane D. 2,3- dimethylhexane |
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| 47. |
Which of the following gases contains the least number of atoms at s.t.p? A. 1 mole of butane B. 4 moles of chlorine C. 3 moles of ozone D. 7 moles of argon Detailed Solution4 moles of chlorine gas = 4Cl\(_2\) = 8 atoms of chlorine3 moles of ozone = 3O\(_3\) = 9 atoms of oxygen 1 mole of butane = C\(_4\)H\(_{10}\) 7 mole of argon = 7Ar = 7 atoms of argon Argon is a monoatomic noble gas with the least number of atoms. There is an explanation video available below. |
|
| 48. |
What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours 30 mins, through molten magnesium chloride? A. 1.12g B. 4.48g C. 1.80g D. 2.00g Detailed SolutionGiven Data:Time (T) = 2hrs 30mins where 2hrs =120mins 2hrs & 30mins = (120 + 30)mins = 150mins 150mins to Seconds = 150 x60 = 9,000s Q = I x T 2 x 9,000 =18,000 where mg has valency of +2 So 2 x 96500 will discharge 24g of mg and 18,000 will discharge xg of mg 2 x 96500 =24 18,000 =x x = \(\frac{24 \times 18,000}{2 x 96500}\) ≈ 2.00g There is an explanation video available below. |
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| 49. |
Which important nitrogen-containing compound is produced in Haber's process? A. NH\(_3\) B. NO\(_2\) C. NO D. HNO\(_3\) |
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| 50. |
Elements in the periodic table are arranged in the order of their A. atomic numbers B. metallic character C. mass number D. relative atomic mass |
| 41. |
Which of the following is a physical change? A. Exposing white phosphorus to air B. Burning kerosene C. Dissolving calcium in water D. Freezing ice cream |
|
| 42. |
In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid? A. 25cm\(^3\) B. 10cm\(^3\) C. 20cm\(^3\) D. 50cm\(^3\) Detailed SolutionEquation of reaction : 2NaOH + H\(_2\)SO\(_4\) → Na\(_2\)SO\(_4\) + 2H\(_2\)OConcentration of a base, CB = 0.5M Volume of acid, V\(_A\) = 10cm\(^3\) Concentration of an acid, C\(_A\) = 1.25M Volume of base, V\(_B\) = ? Recall: \(\frac{C_A V_A}{C_B V_B} = \frac{n_A}{n_B}\) ... (1) N.B: From the equation, \(\frac{n_A}{n_B} = \frac{1}{2}\) From (1) \(\frac{1.25 \times 10}{0.5 \times V_B} = \frac{1}{2}\) \(\frac{12.5}{0.5V_B} = \frac{1}{2}\) 25 = 0.5V\(_B\) VB = 50.0 cm\(^3\) There is an explanation video available below.&l |
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| 43. |
Sulphur exists in six forms in the solid state. This property is known as A. Isomerism B. Allotropy C. Isotopy D. Isomorphism |
|
| 44. |
In the reaction: A. Adding a suitable catalyst B. Increasing the concentration of P C. Increasing the temperature D. Decreasing the temperature |
|
| 45. |
A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula. A. C\(_3\)H\(_6\)O\(_3\) B. C\(_6\)H\(_6\)O\(_3\) C. C\(_6\)H\(_{12}\)O\(_6\) D. CH\(_2\)O |
| 46. |
The IUPAC nomenclature of the compound A. 3,4- dimethylhexane B. 2,3- dimethyl pentane C. 2- ethyl hexane D. 2,3- dimethylhexane |
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| 47. |
Which of the following gases contains the least number of atoms at s.t.p? A. 1 mole of butane B. 4 moles of chlorine C. 3 moles of ozone D. 7 moles of argon Detailed Solution4 moles of chlorine gas = 4Cl\(_2\) = 8 atoms of chlorine3 moles of ozone = 3O\(_3\) = 9 atoms of oxygen 1 mole of butane = C\(_4\)H\(_{10}\) 7 mole of argon = 7Ar = 7 atoms of argon Argon is a monoatomic noble gas with the least number of atoms. There is an explanation video available below. |
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| 48. |
What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours 30 mins, through molten magnesium chloride? A. 1.12g B. 4.48g C. 1.80g D. 2.00g Detailed SolutionGiven Data:Time (T) = 2hrs 30mins where 2hrs =120mins 2hrs & 30mins = (120 + 30)mins = 150mins 150mins to Seconds = 150 x60 = 9,000s Q = I x T 2 x 9,000 =18,000 where mg has valency of +2 So 2 x 96500 will discharge 24g of mg and 18,000 will discharge xg of mg 2 x 96500 =24 18,000 =x x = \(\frac{24 \times 18,000}{2 x 96500}\) ≈ 2.00g There is an explanation video available below. |
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| 49. |
Which important nitrogen-containing compound is produced in Haber's process? A. NH\(_3\) B. NO\(_2\) C. NO D. HNO\(_3\) |
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| 50. |
Elements in the periodic table are arranged in the order of their A. atomic numbers B. metallic character C. mass number D. relative atomic mass |