Year :
2019
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
41 - 50 of 50 Questions
| # | Question | Ans |
|---|---|---|
| 41. |
Which of the following substances can be classified as heavy chemicals? A. CaOCl\(_2\) B. H\(_2\)SO\(_4\) C. AgNO\(_3\) D. CaO Detailed Solution- heavy chemicals are produced and handled in large lots and are often in a crude state.- Some examples of bulk chemicals are ammonia, sulfuric acid, and sodium hydroxide - Fine chemicals are single, pure and complex chemicals that are only produced in small amounts |
|
| 42. |
In Boyle's law, ................................ A. T is constant, P varies directly with V B. P is constant, V varies inversely with T C. V is constant, P varies directly with T D. T is constant, V varies inversely with P Detailed SolutionBoyle's law states that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature; i.e., in equation form, pv = k, a constant. ... |
|
| 43. |
Which of the following apparatus is NOT used in volumetric analysis? A. Pipette B. Burette C. Desiccator D. conical flask Detailed Solution- The most common apparatus used in volumetric determinations are the pipette,buret, measuring cylinder, volumetric and conical (titration) flask.- A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity. |
|
| 44. |
One of the deductions from Rutherford's alpha particle scattering experiment is that? A. electrons are negatively charged B. electrons have a negligible mass C. nuclei of atoms are positively charged D. protons are positively charged Detailed SolutionThe model of an atom put forward by Ernest Rutherford in 1911 on the basis of experiments on the scattering of alpha particles. The model consisted of a very dense positively charged nucleus, with electrons orbiting round the nucleus. |
|
| 45. |
The atoms of \(^{64}_{29}\)Cu and \(^{65}_{30}\)Zn have the same number of? A. nucleon B. electrons C. neutrons D. protons Detailed SolutionThe atomic mass is written as superscript = proton number + neutron number- Atomic mass of Cu is 64 = 29 + 35 - Atomic mass of Zn is 65 = 30 + 35 Proton number is written as subscript |
|
| 46. |
The number of electrons in the 3d orbital of \(_24\)Cr is A. 2 B. 3 C. 4 D. 5 Detailed SolutionIts electronic configuration in ground state is 1s2 2s2 2p6 3s2 3p6 4s1 3d5. |
|
| 47. |
The method used to collect gas in the laboratory depends on its?I. boiling point II. density III. smell IV. solubility in water A. i and ii only B. ii and iv only C. iii and iv D. i, ii, iii and iv Detailed SolutionThe method of collecting a gas produced by a chemical reaction will depend on its solubility and its density. |
|
| 48. |
Which of the following methods is NOT used for the separation of mixtures? A. Chromatography B. Crystallization C. Distillation D. Electrolysis Detailed SolutionUses of electrolysis: |
|
| 49. |
The group to which elements belong in the periodic table is determined by the number? A. electrons B. core electrons C. valence shells D. valence electrons Detailed SolutionThis periodic table shows the valences of element groups. |
|
| 50. |
Kipps apparatus can be used to prepare? A. H\(_2\) B. NH\(_3\) C. O\(_2\) D. H\(_2\)S Detailed SolutionKipp's apparatus is a laboratory apparatus specially designed for producing small amount of gases and is used to produce usually hydrogen sulfide. |
| 41. |
Which of the following substances can be classified as heavy chemicals? A. CaOCl\(_2\) B. H\(_2\)SO\(_4\) C. AgNO\(_3\) D. CaO Detailed Solution- heavy chemicals are produced and handled in large lots and are often in a crude state.- Some examples of bulk chemicals are ammonia, sulfuric acid, and sodium hydroxide - Fine chemicals are single, pure and complex chemicals that are only produced in small amounts |
|
| 42. |
In Boyle's law, ................................ A. T is constant, P varies directly with V B. P is constant, V varies inversely with T C. V is constant, P varies directly with T D. T is constant, V varies inversely with P Detailed SolutionBoyle's law states that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature; i.e., in equation form, pv = k, a constant. ... |
|
| 43. |
Which of the following apparatus is NOT used in volumetric analysis? A. Pipette B. Burette C. Desiccator D. conical flask Detailed Solution- The most common apparatus used in volumetric determinations are the pipette,buret, measuring cylinder, volumetric and conical (titration) flask.- A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity. |
|
| 44. |
One of the deductions from Rutherford's alpha particle scattering experiment is that? A. electrons are negatively charged B. electrons have a negligible mass C. nuclei of atoms are positively charged D. protons are positively charged Detailed SolutionThe model of an atom put forward by Ernest Rutherford in 1911 on the basis of experiments on the scattering of alpha particles. The model consisted of a very dense positively charged nucleus, with electrons orbiting round the nucleus. |
|
| 45. |
The atoms of \(^{64}_{29}\)Cu and \(^{65}_{30}\)Zn have the same number of? A. nucleon B. electrons C. neutrons D. protons Detailed SolutionThe atomic mass is written as superscript = proton number + neutron number- Atomic mass of Cu is 64 = 29 + 35 - Atomic mass of Zn is 65 = 30 + 35 Proton number is written as subscript |
| 46. |
The number of electrons in the 3d orbital of \(_24\)Cr is A. 2 B. 3 C. 4 D. 5 Detailed SolutionIts electronic configuration in ground state is 1s2 2s2 2p6 3s2 3p6 4s1 3d5. |
|
| 47. |
The method used to collect gas in the laboratory depends on its?I. boiling point II. density III. smell IV. solubility in water A. i and ii only B. ii and iv only C. iii and iv D. i, ii, iii and iv Detailed SolutionThe method of collecting a gas produced by a chemical reaction will depend on its solubility and its density. |
|
| 48. |
Which of the following methods is NOT used for the separation of mixtures? A. Chromatography B. Crystallization C. Distillation D. Electrolysis Detailed SolutionUses of electrolysis: |
|
| 49. |
The group to which elements belong in the periodic table is determined by the number? A. electrons B. core electrons C. valence shells D. valence electrons Detailed SolutionThis periodic table shows the valences of element groups. |
|
| 50. |
Kipps apparatus can be used to prepare? A. H\(_2\) B. NH\(_3\) C. O\(_2\) D. H\(_2\)S Detailed SolutionKipp's apparatus is a laboratory apparatus specially designed for producing small amount of gases and is used to produce usually hydrogen sulfide. |