Year :
2000
Title :
Chemistry
Exam :
WASSCE/WAEC MAY/JUNE
Paper 1 | Objectives
21 - 30 of 45 Questions
| # | Question | Ans |
|---|---|---|
| 21. |
Chemical equilibrium is attained when A. reactants in the system are used up B. concentrations of the products are greater than those of the reactants C. concentrations of the reactants and products remain constant D. reactants stop forming the products |
C |
| 22. |
What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1 A. Decreases the value of ∆H B. Increases the collision rate of reactant particles C. Shifts equilibrium position to the right D. Reduces the time for attainment of equilibrium |
A |
| 23. |
A finely divided from of a metal burns more readily in air than the rod from because the rod has A. higher molar mass B. smaller surface area C. protective oxide coating D. diferent chemical properties |
B |
| 24. |
Which of the following will displace copper from a solution of copper (ll) salt? A. Aluminium ions B. Magnesium C. Silver D. Zinc ions |
B |
| 25. |
What is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O A. 1 B. 6 C. 8 D. 12 |
B |
| 26. |
In which of the following is the oxidation number of sulphur equal to -2? A. S8 B. H2S C. SO 2 D. SO 3 2- |
B |
| 27. |
An iron nail placed in a solution copper (ll) tetraoxosulphate (VI) is soon covered with a deposit of copper which of the following equations represents the reactions ? A. Fe 2+ (aq) + Cu(s) → Fe 3+ + Cu 2+ (aq) B. Fe 2+ (aq) + Cu(s) → Fe(s) + Cu2+ (aq) C. Fe (s) + Cu2+ (aq) → Fe2+(aq) + Cu2+ (aq) D. Fe(s) + Cu2+ → Fe2+(aq) + Cu(s) |
D |
| 28. |
0.10 mol dm-3 NaCI conducts electricity better than 0.10 mol dm-3 CH3COOH because the solution of NaCI A. contains more ions B. is neutral to litmus C. has a lower molar mass D. has a higher pH |
A |
| 29. |
Which of the following occurs when a solution of CuSO4 is electrolysed using copper electrodes? A. The cathode becomes coated with copper B. Both electrodes gain electrons C. The blue colour of the solution fades gradually D. The anode increases in mass |
A |
| 30. |
Which of the following procedures is suitable for identifying the food colouring added to a pastry sample? A. carry out some food tests B. examine the pastry sample under a microscope C. Do a chromatogram of the colouring extract D. .determine the molar mass of the colouring Detailed SolutionChromatography is used for quality control in the food industry, by separating and analyzing additives, vitamins, preservatives, proteins, and amino acids. It can also separate and detect contaminants such as aflatoxin, a cancer-causing chemical produced by a mold on peanuts. |
| 21. |
Chemical equilibrium is attained when A. reactants in the system are used up B. concentrations of the products are greater than those of the reactants C. concentrations of the reactants and products remain constant D. reactants stop forming the products |
C |
| 22. |
What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1 A. Decreases the value of ∆H B. Increases the collision rate of reactant particles C. Shifts equilibrium position to the right D. Reduces the time for attainment of equilibrium |
A |
| 23. |
A finely divided from of a metal burns more readily in air than the rod from because the rod has A. higher molar mass B. smaller surface area C. protective oxide coating D. diferent chemical properties |
B |
| 24. |
Which of the following will displace copper from a solution of copper (ll) salt? A. Aluminium ions B. Magnesium C. Silver D. Zinc ions |
B |
| 25. |
What is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O A. 1 B. 6 C. 8 D. 12 |
B |
| 26. |
In which of the following is the oxidation number of sulphur equal to -2? A. S8 B. H2S C. SO 2 D. SO 3 2- |
B |
| 27. |
An iron nail placed in a solution copper (ll) tetraoxosulphate (VI) is soon covered with a deposit of copper which of the following equations represents the reactions ? A. Fe 2+ (aq) + Cu(s) → Fe 3+ + Cu 2+ (aq) B. Fe 2+ (aq) + Cu(s) → Fe(s) + Cu2+ (aq) C. Fe (s) + Cu2+ (aq) → Fe2+(aq) + Cu2+ (aq) D. Fe(s) + Cu2+ → Fe2+(aq) + Cu(s) |
D |
| 28. |
0.10 mol dm-3 NaCI conducts electricity better than 0.10 mol dm-3 CH3COOH because the solution of NaCI A. contains more ions B. is neutral to litmus C. has a lower molar mass D. has a higher pH |
A |
| 29. |
Which of the following occurs when a solution of CuSO4 is electrolysed using copper electrodes? A. The cathode becomes coated with copper B. Both electrodes gain electrons C. The blue colour of the solution fades gradually D. The anode increases in mass |
A |
| 30. |
Which of the following procedures is suitable for identifying the food colouring added to a pastry sample? A. carry out some food tests B. examine the pastry sample under a microscope C. Do a chromatogram of the colouring extract D. .determine the molar mass of the colouring Detailed SolutionChromatography is used for quality control in the food industry, by separating and analyzing additives, vitamins, preservatives, proteins, and amino acids. It can also separate and detect contaminants such as aflatoxin, a cancer-causing chemical produced by a mold on peanuts. |