Year :
2019
Title :
Chemistry
Exam :
JAMB Exam
Paper 1 | Objectives
21 - 30 of 80 Questions
| # | Question | Ans |
|---|---|---|
| 21. |
When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called A. electrovalent bond B. compound bond C. ionic bond D. covalent bond Detailed SolutionWhen ammonia and hydrogen ion go into bonding, they form ammonium ion with a one dative covalent bond and three covalent bonds.There is an explanation video available below. |
|
| 22. |
Which of the following represents the kind of bonding present in ammonium chloride? A. ionic only B. covalent only C. ionic and covalent D. dative covalent |
|
| 23. |
Consider the reaction A. the equilibrium will shift B. rate of forward reaction will increase C. rate of backward reaction will increase D. rates of forward and backward reaction are not affected Detailed SolutionGiven: The equation belowA\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\) According to Le Chatelier's Principle: Pressure changes affects only the gaseous reactants and products There must be different amount of gaseous particles on both sides. Generally; a decrease in the pressure shifts the equilibrium position in favor of the side with larger volume of gases. I.e rates of backward reaction. NB: This is a correction to the video explanation. There is an explanation video available below. |
|
| 24. |
For the general equation of the nature A. k[P]\(^x\)[Q]\(^y\) B. \(\frac{m[R][S]}{x[P]y[Q]}\) C. \(\frac{[P]^x[Q]^y}{[R]^m[S]^n}\) D. \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\) Detailed SolutionGiven:xP + yQ ⇌ mR + nS Let us assume they are all in aqueous solution k = \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\) There is an explanation video available below. |
|
| 25. |
Which of the following reactions is an oxidation process? A. 2H\(^+\) + 2e\(^-\) \(\to\) H\(_2\) B. 2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\) C. OCl\(^-\) + H\(_2\)O + 2e\(^-\) \(\to\) 2OH\(^-\) + Cl\(^-\) D. Cl + e\(^-\) \(\to\) Cl\(^-\) |
|
| 26. |
If acidified Potassium Dichromate(VI) (K\(_2\)Cr\(_2\)O\(_7\)) acts as oxidizing agent, color changes from A. yellow to green B. orange to green C. yellow to red D. orange to red Detailed SolutionPotassium dichromate is an oxidising agent in organic chemistry. It is used to oxidize alcohols.In an aqueous solution the color change exhibited can be used to test for distinguishing aldehydes from ketones. Aldehydes reduce dichromate from the +6 to the +3 oxidation state, changing color from orange to green. This color change arises because the aldehyde can be oxidized to the corresponding carboxylic acid. There is an explanation video available below. |
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| 27. |
The heat of formation of ethene, C\(_2\)H\(_4\) is 50 kJmol\(^{-1}\), and that of ethane, C\(_2\)H\(_6\) is -82kJmol\(^{-1}\). Calculate the heat evolved in the process:C\(_2\)H\(_4\) + H\(_2\) \(\to\) C\(_2\)H\(_6\) A. -122kJ B. -132kJ C. -88kJ D. -60kJ |
|
| 28. |
Which of the following statements about catalyst is false? A. biological catalysts are called enzymes B. catalyst do not appear in the balanced equation C. catalyst reduce the activation energy for a reaction D. catalysts do not alter the mechanism of the reaction and never appear in the rate low |
|
| 29. |
Which of the following does not support the fact that air is a mixture? A. the constituents of air are in a fixed proportion by mass B. it cannot be represented with a chemical formula C. the constituents of air can be separated by physical by physical means D. none of the above |
|
| 30. |
What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)? A. Fractional crystallization B. Fractional distillation C. Filtration D. Evaporation |
| 21. |
When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called A. electrovalent bond B. compound bond C. ionic bond D. covalent bond Detailed SolutionWhen ammonia and hydrogen ion go into bonding, they form ammonium ion with a one dative covalent bond and three covalent bonds.There is an explanation video available below. |
|
| 22. |
Which of the following represents the kind of bonding present in ammonium chloride? A. ionic only B. covalent only C. ionic and covalent D. dative covalent |
|
| 23. |
Consider the reaction A. the equilibrium will shift B. rate of forward reaction will increase C. rate of backward reaction will increase D. rates of forward and backward reaction are not affected Detailed SolutionGiven: The equation belowA\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\) According to Le Chatelier's Principle: Pressure changes affects only the gaseous reactants and products There must be different amount of gaseous particles on both sides. Generally; a decrease in the pressure shifts the equilibrium position in favor of the side with larger volume of gases. I.e rates of backward reaction. NB: This is a correction to the video explanation. There is an explanation video available below. |
|
| 24. |
For the general equation of the nature A. k[P]\(^x\)[Q]\(^y\) B. \(\frac{m[R][S]}{x[P]y[Q]}\) C. \(\frac{[P]^x[Q]^y}{[R]^m[S]^n}\) D. \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\) Detailed SolutionGiven:xP + yQ ⇌ mR + nS Let us assume they are all in aqueous solution k = \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\) There is an explanation video available below. |
|
| 25. |
Which of the following reactions is an oxidation process? A. 2H\(^+\) + 2e\(^-\) \(\to\) H\(_2\) B. 2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\) C. OCl\(^-\) + H\(_2\)O + 2e\(^-\) \(\to\) 2OH\(^-\) + Cl\(^-\) D. Cl + e\(^-\) \(\to\) Cl\(^-\) |
| 26. |
If acidified Potassium Dichromate(VI) (K\(_2\)Cr\(_2\)O\(_7\)) acts as oxidizing agent, color changes from A. yellow to green B. orange to green C. yellow to red D. orange to red Detailed SolutionPotassium dichromate is an oxidising agent in organic chemistry. It is used to oxidize alcohols.In an aqueous solution the color change exhibited can be used to test for distinguishing aldehydes from ketones. Aldehydes reduce dichromate from the +6 to the +3 oxidation state, changing color from orange to green. This color change arises because the aldehyde can be oxidized to the corresponding carboxylic acid. There is an explanation video available below. |
|
| 27. |
The heat of formation of ethene, C\(_2\)H\(_4\) is 50 kJmol\(^{-1}\), and that of ethane, C\(_2\)H\(_6\) is -82kJmol\(^{-1}\). Calculate the heat evolved in the process:C\(_2\)H\(_4\) + H\(_2\) \(\to\) C\(_2\)H\(_6\) A. -122kJ B. -132kJ C. -88kJ D. -60kJ |
|
| 28. |
Which of the following statements about catalyst is false? A. biological catalysts are called enzymes B. catalyst do not appear in the balanced equation C. catalyst reduce the activation energy for a reaction D. catalysts do not alter the mechanism of the reaction and never appear in the rate low |
|
| 29. |
Which of the following does not support the fact that air is a mixture? A. the constituents of air are in a fixed proportion by mass B. it cannot be represented with a chemical formula C. the constituents of air can be separated by physical by physical means D. none of the above |
|
| 30. |
What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)? A. Fractional crystallization B. Fractional distillation C. Filtration D. Evaporation |