Year :
2020
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
41 - 49 of 49 Questions
| # | Question | Ans |
|---|---|---|
| 41. |
The metallic bond in magnesium is stronger than that in calcium because magnesium has a A. larger atomic size. B. smaller atomic size C. greater number of valence electrons D. lower melting point Detailed Solution- Magnessium has a stronger metallic bond than calcium because it has smaller atomic radius.- Atomic radius decreases across a period and increases down a group. |
|
| 42. |
Consider the reaction represented by the following equation:AgNO\(_3\) + NaCl → AgCl + NaNO\(_3\).The steps that could be taken to obtain pure dry sample of AgCI (s) from the mixture includes A. heating to saturation and drying B. filtering and evaporation to dryness C. filtering, washing and drying D. crystallizing and allowing to cool |
C |
| 43. |
How many electrons does \({31}_{15}\)P\(^3-\) contain? A. 12 B. 15 C. 16 D. 18 Detailed Solution- Phosphorus also has 15 electrons.- Here we have P3- which means that this atom has gained 3 electrons. So, P3- has 18 electrons. |
|
| 44. |
The atomic number of an atom would be equal to its mass number if it A. has a totally filled valence shell B. has a high charge to mass ratio C. does not contain neutrons D. exhibits isotopy Detailed Solution- The mass number of an atom is its total number of protons and neutrons |
|
| 45. |
Which of the following processes is not exhibited by atoms in order to attain more stable electron configuration? A. Gaining of electrons B. Hybridization of orbitals C. Losing electrons D. Sharing electron Detailed Solution- An atom may give, take, or share electrons with another atom to achieve a full valence shell, the most stable electron configuration.- Hybrid orbitals are useful in the explanation of molecular geometry and atomic bonding properties and are symmetrically disposed in space. |
|
| 46. |
Which of the following quantities is a molar quantity? A. Molarity B. Molar mass C. Mass concentration D. Molality |
C |
| 47. |
Dilution factor is the? A. amount of distilled water that is added to the concentrated solution to dilute it B. Quantity of distilled water added to l dm\(^3\) of the concentrated solution to give the dilute solution C. number of times the volume of the concentrated solution is diluted to give the dilute solution D. act of diluting the concentrated solution to obtain the dilute solution Detailed Solution- Dilution Factor is the factor by which the stock solution is diluted. It may be expressed as the ratio of the volume of the final diluted solution (V2) to the initial volume removed from the stock solution (V1)- The dilution factor is the total number of unit volumes in which your material will be dissolved. |
|
| 48. |
Calcium chloride is an ionic compound. Which of the following statements account for its ionic character?I. Calcium has high ionization energy. II. Calcium has low ionization energy. III. Chlorine has high electron affinity. IV. Chlorine has high Ionization energy. A. I and Il only B. I, II and IV only C. II, IIl and IV only D. I, II, III and IV Detailed Solution- CaCl2 is an ionic compound owing to the large electronegative difference between the calcium atom and chlorine atom, which is greater than 2.0. In calcium chloride, the calcium atom donates its two electrons and become cation whereas each chlorine atom gain one electron, donated by Calcium, and get a negative charge.- Ionization energies are always positive numbers, because energy must be supplied (an endothermic energy change) to separate electrons from atoms. - Chlorine has a high ionization energy - Chlorine has high electron affinity among the elements. Its high affinity can be attributed to its large atomic radius, or size. Because chlorine's outermost orbi |
|
| 49. |
An example of a biodegradable pollutant is? A. plastic B. sewage C. carbon (II) oxide D. hydrogen sulphide Detailed Solutionexamples of biodegradable- Glass, metals, electronic devices, computer parts, batteries, medical waste, plastic bags, plastic bottles, tetra packs, and carbon paper are a few examples of non- biodegradable materials. |
| 41. |
The metallic bond in magnesium is stronger than that in calcium because magnesium has a A. larger atomic size. B. smaller atomic size C. greater number of valence electrons D. lower melting point Detailed Solution- Magnessium has a stronger metallic bond than calcium because it has smaller atomic radius.- Atomic radius decreases across a period and increases down a group. |
|
| 42. |
Consider the reaction represented by the following equation:AgNO\(_3\) + NaCl → AgCl + NaNO\(_3\).The steps that could be taken to obtain pure dry sample of AgCI (s) from the mixture includes A. heating to saturation and drying B. filtering and evaporation to dryness C. filtering, washing and drying D. crystallizing and allowing to cool |
C |
| 43. |
How many electrons does \({31}_{15}\)P\(^3-\) contain? A. 12 B. 15 C. 16 D. 18 Detailed Solution- Phosphorus also has 15 electrons.- Here we have P3- which means that this atom has gained 3 electrons. So, P3- has 18 electrons. |
|
| 44. |
The atomic number of an atom would be equal to its mass number if it A. has a totally filled valence shell B. has a high charge to mass ratio C. does not contain neutrons D. exhibits isotopy Detailed Solution- The mass number of an atom is its total number of protons and neutrons |
|
| 45. |
Which of the following processes is not exhibited by atoms in order to attain more stable electron configuration? A. Gaining of electrons B. Hybridization of orbitals C. Losing electrons D. Sharing electron Detailed Solution- An atom may give, take, or share electrons with another atom to achieve a full valence shell, the most stable electron configuration.- Hybrid orbitals are useful in the explanation of molecular geometry and atomic bonding properties and are symmetrically disposed in space. |
| 46. |
Which of the following quantities is a molar quantity? A. Molarity B. Molar mass C. Mass concentration D. Molality |
C |
| 47. |
Dilution factor is the? A. amount of distilled water that is added to the concentrated solution to dilute it B. Quantity of distilled water added to l dm\(^3\) of the concentrated solution to give the dilute solution C. number of times the volume of the concentrated solution is diluted to give the dilute solution D. act of diluting the concentrated solution to obtain the dilute solution Detailed Solution- Dilution Factor is the factor by which the stock solution is diluted. It may be expressed as the ratio of the volume of the final diluted solution (V2) to the initial volume removed from the stock solution (V1)- The dilution factor is the total number of unit volumes in which your material will be dissolved. |
|
| 48. |
Calcium chloride is an ionic compound. Which of the following statements account for its ionic character?I. Calcium has high ionization energy. II. Calcium has low ionization energy. III. Chlorine has high electron affinity. IV. Chlorine has high Ionization energy. A. I and Il only B. I, II and IV only C. II, IIl and IV only D. I, II, III and IV Detailed Solution- CaCl2 is an ionic compound owing to the large electronegative difference between the calcium atom and chlorine atom, which is greater than 2.0. In calcium chloride, the calcium atom donates its two electrons and become cation whereas each chlorine atom gain one electron, donated by Calcium, and get a negative charge.- Ionization energies are always positive numbers, because energy must be supplied (an endothermic energy change) to separate electrons from atoms. - Chlorine has a high ionization energy - Chlorine has high electron affinity among the elements. Its high affinity can be attributed to its large atomic radius, or size. Because chlorine's outermost orbi |
|
| 49. |
An example of a biodegradable pollutant is? A. plastic B. sewage C. carbon (II) oxide D. hydrogen sulphide Detailed Solutionexamples of biodegradable- Glass, metals, electronic devices, computer parts, batteries, medical waste, plastic bags, plastic bottles, tetra packs, and carbon paper are a few examples of non- biodegradable materials. |