Year :
2017
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
11 - 20 of 50 Questions
| # | Question | Ans |
|---|---|---|
| 11. |
The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is A. +2 B. +3 C. +4 D. +5 Detailed Solution\(Pb(NO_{3})_{2}\) = \(+2 +2N + (-2\times 6) = 0\)= \(2N = 10\) ⇒ \(N = +5\) |
|
| 12. |
Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements? A. Na, Al, P, Cl B. Cl, P, Al, Na C. Na, P, Cl, Al D. Al, Na, P, Cl Detailed SolutionAs you move across a period, first ionization energy increases. |
|
| 13. |
Which of the following metals has the strongest metallic bond? A. \(_{13}Al\) B. \(_{19}K\) C. \(_{12}Mg\) D. \(_{11}Na\) Detailed SolutionAluminium has the highest magnitude of charge of +3, hence it will form a stronger metallic bond. |
|
| 14. |
Which of the following substances does not have van der Waals' forces? A. Copper B. Graphite C. Neon D. Iodine crystals |
A |
| 15. |
The oxidation number of X in \(XO_{4}^{3+}\) is A. +1 B. +3 C. +4 D. +5 Detailed Solution\(XO_{4}^{3+}\) = \(X + (-2\times 4) = -3\)\(X = -3+8 = +5\) |
|
| 16. |
The ionization energy is affected by the following factors except A. distance of the outermost electron(s) from the nucleus B. size of the positive nuclear charge C. ability to attract shared electron(s) D. screening effect of the inner electron(s) Detailed SolutionThese 3 factors affect the ionization energy: |
|
| 17. |
Which of the following statements is correct? A. Covalent compounds would readily ionize in solution B. Covalent compounds consist of ions C. Hydrogen bond is formed between a metal and a non-metal D. Ionic compounds in solution would conduct electricity Detailed SolutionOne of the common features of materials with ionic bonds is that they conduct electricity when dissolved in water. |
|
| 18. |
The bond angle in tetrahedral molecules such as tetrachloromethane is A. 180.0° B. 109.5° C. 105.5° D. 90.0° |
B |
| 19. |
The properties of a good primary standard include the following except A. high molecular mass B. low molecular mass C. high degree of purity D. readily available Detailed SolutionCharacters of a good primary standard include: high purity, low reactivity with the air or surrounding environment, low hygroscopicity, large molar mass, a predictable reactivity and readily available. |
|
| 20. |
The use of diamond in abrasives is due to its A. high melting point B. hardness C. octahedral shape D. durability Detailed SolutionDiamonds are very hard, they are often used as an abrasive. |
| 11. |
The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is A. +2 B. +3 C. +4 D. +5 Detailed Solution\(Pb(NO_{3})_{2}\) = \(+2 +2N + (-2\times 6) = 0\)= \(2N = 10\) ⇒ \(N = +5\) |
|
| 12. |
Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements? A. Na, Al, P, Cl B. Cl, P, Al, Na C. Na, P, Cl, Al D. Al, Na, P, Cl Detailed SolutionAs you move across a period, first ionization energy increases. |
|
| 13. |
Which of the following metals has the strongest metallic bond? A. \(_{13}Al\) B. \(_{19}K\) C. \(_{12}Mg\) D. \(_{11}Na\) Detailed SolutionAluminium has the highest magnitude of charge of +3, hence it will form a stronger metallic bond. |
|
| 14. |
Which of the following substances does not have van der Waals' forces? A. Copper B. Graphite C. Neon D. Iodine crystals |
A |
| 15. |
The oxidation number of X in \(XO_{4}^{3+}\) is A. +1 B. +3 C. +4 D. +5 Detailed Solution\(XO_{4}^{3+}\) = \(X + (-2\times 4) = -3\)\(X = -3+8 = +5\) |
| 16. |
The ionization energy is affected by the following factors except A. distance of the outermost electron(s) from the nucleus B. size of the positive nuclear charge C. ability to attract shared electron(s) D. screening effect of the inner electron(s) Detailed SolutionThese 3 factors affect the ionization energy: |
|
| 17. |
Which of the following statements is correct? A. Covalent compounds would readily ionize in solution B. Covalent compounds consist of ions C. Hydrogen bond is formed between a metal and a non-metal D. Ionic compounds in solution would conduct electricity Detailed SolutionOne of the common features of materials with ionic bonds is that they conduct electricity when dissolved in water. |
|
| 18. |
The bond angle in tetrahedral molecules such as tetrachloromethane is A. 180.0° B. 109.5° C. 105.5° D. 90.0° |
B |
| 19. |
The properties of a good primary standard include the following except A. high molecular mass B. low molecular mass C. high degree of purity D. readily available Detailed SolutionCharacters of a good primary standard include: high purity, low reactivity with the air or surrounding environment, low hygroscopicity, large molar mass, a predictable reactivity and readily available. |
|
| 20. |
The use of diamond in abrasives is due to its A. high melting point B. hardness C. octahedral shape D. durability Detailed SolutionDiamonds are very hard, they are often used as an abrasive. |