Year :
1991
Title :
Chemistry
Exam :
JAMB Exam
Paper 1 | Objectives
1 - 10 of 49 Questions
| # | Question | Ans |
|---|---|---|
| 1. |
Which of the following can be obtained by fractional distillation? A. Nitrogen from liquid air B. Sodium chloride from sea water C. Iodine from a solution of Iondine in carbon tetrachloride D. Sulphur from a solution of sulphur incarbon disulphide |
A |
| 2. |
Which of the following are mixtures? A. i, ii and iii B. i, ii and iv C. i and ii only D. i and iv |
A |
| 3. |
An iron ore is known to contain 70.0% Fe2O3. The obtain from 80kg of the ore is? A. 35.0 kg B. 39.2 kg C. 70.0 kg D. 78.4 kg Detailed Solution2Fe2O3 → 4Fe + 3O2320g 224g 96g (70) / (100) x (80) / (1) 56g if 0.32kg of Fe293 contains 0.224 kg Then 56kg will contain (56 x 0.224) / (0.32) =39.2 kg |
|
| 4. |
In two separate experiments, 0.36g and 0.71g of chlorine combined with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20g and 0.40g of X respectively. The data above represents the law of ? A. multiple proportion B. conservation of mass C. constant composition D. reciprocal proportion Detailed Solution0.36g of Cl combines with 0.2g of x1g of Cl will combine with \(\frac{1 \times 0.2}{0.32}\) = 0.56 0.71g of U combines with 0.49g of x 1g of U will combine with \(\frac{1 \times 0.4}{71}\) = 0.56 Ratio 0.56 : 0.56 = 1:1 |
|
| 5. |
30cm\(^3\) of oxygen at 10 atmospheres pressure is placed in a 20 cm\(^3\) container. Calculate the new pressure if temperature is kept constant? A. 6.7 atm B. 15.0 atm C. 60.0 atm D. 0 atm Detailed SolutionP\(_1\)V\(_1\) = P\(_2\)V\(_2\) (where T is kept constant)30 x 10 = P\(_2\) x 20 P\(_2\) = \(\frac{30 \times 10}{20}\) = 15.0 atm |
|
| 6. |
Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat? A. 28 dm3 B. 56 dm3 C. 112 dm3 D. 196 dm3 Detailed Solution2KHCOdm3 → K2CO3 + H2O + CO22(39 + 1 + 12 + 48) 22.4 dm3 200 g 22.4 dm3 of CO2 1000 g (1000) / (200) x 22.4 = 112 dm3 |
|
| 7. |
A given quantity of a gas occupies a volume of 228 cm3 at a pressure of 750mm Hg. What will be its volume at atmospheric pressure? A. 220 cm3 B. 225 cm3 C. 230 cm3 D. 235 cm3 Detailed SolutionP1V1 = P2V2 ∴ 750 x 228 = 760 V2V2 = (750 x 228 cm3) / (760) = 225 cm3 |
|
| 8. |
A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 20°C. The number of moles of gas in the sample is? A. 1.00 B. 2.00 C. 3.00 D. 4.00 Detailed SolutionPV = nRT2.93 x 8.2 = 0.082 x 293 xn ∴ n = (2.93 x8.2) / (0.082 x 293) n = 1 |
|
| 9. |
Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed? A. has formula XY B. is likely to be ionic C. contains X2+ ions D. contains Y- ions Detailed SolutionThe compound formed by a mixture of X and Y will be \(XY_{2}\) not XY. |
|
| 10. |
The electronic configuration of an elements is 1s22s22p63s23p3. How many unpaired electrons are there in the element? A. 5 B. 4 C. 3 D. 2 |
C |
| 1. |
Which of the following can be obtained by fractional distillation? A. Nitrogen from liquid air B. Sodium chloride from sea water C. Iodine from a solution of Iondine in carbon tetrachloride D. Sulphur from a solution of sulphur incarbon disulphide |
A |
| 2. |
Which of the following are mixtures? A. i, ii and iii B. i, ii and iv C. i and ii only D. i and iv |
A |
| 3. |
An iron ore is known to contain 70.0% Fe2O3. The obtain from 80kg of the ore is? A. 35.0 kg B. 39.2 kg C. 70.0 kg D. 78.4 kg Detailed Solution2Fe2O3 → 4Fe + 3O2320g 224g 96g (70) / (100) x (80) / (1) 56g if 0.32kg of Fe293 contains 0.224 kg Then 56kg will contain (56 x 0.224) / (0.32) =39.2 kg |
|
| 4. |
In two separate experiments, 0.36g and 0.71g of chlorine combined with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20g and 0.40g of X respectively. The data above represents the law of ? A. multiple proportion B. conservation of mass C. constant composition D. reciprocal proportion Detailed Solution0.36g of Cl combines with 0.2g of x1g of Cl will combine with \(\frac{1 \times 0.2}{0.32}\) = 0.56 0.71g of U combines with 0.49g of x 1g of U will combine with \(\frac{1 \times 0.4}{71}\) = 0.56 Ratio 0.56 : 0.56 = 1:1 |
|
| 5. |
30cm\(^3\) of oxygen at 10 atmospheres pressure is placed in a 20 cm\(^3\) container. Calculate the new pressure if temperature is kept constant? A. 6.7 atm B. 15.0 atm C. 60.0 atm D. 0 atm Detailed SolutionP\(_1\)V\(_1\) = P\(_2\)V\(_2\) (where T is kept constant)30 x 10 = P\(_2\) x 20 P\(_2\) = \(\frac{30 \times 10}{20}\) = 15.0 atm |
| 6. |
Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat? A. 28 dm3 B. 56 dm3 C. 112 dm3 D. 196 dm3 Detailed Solution2KHCOdm3 → K2CO3 + H2O + CO22(39 + 1 + 12 + 48) 22.4 dm3 200 g 22.4 dm3 of CO2 1000 g (1000) / (200) x 22.4 = 112 dm3 |
|
| 7. |
A given quantity of a gas occupies a volume of 228 cm3 at a pressure of 750mm Hg. What will be its volume at atmospheric pressure? A. 220 cm3 B. 225 cm3 C. 230 cm3 D. 235 cm3 Detailed SolutionP1V1 = P2V2 ∴ 750 x 228 = 760 V2V2 = (750 x 228 cm3) / (760) = 225 cm3 |
|
| 8. |
A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 20°C. The number of moles of gas in the sample is? A. 1.00 B. 2.00 C. 3.00 D. 4.00 Detailed SolutionPV = nRT2.93 x 8.2 = 0.082 x 293 xn ∴ n = (2.93 x8.2) / (0.082 x 293) n = 1 |
|
| 9. |
Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed? A. has formula XY B. is likely to be ionic C. contains X2+ ions D. contains Y- ions Detailed SolutionThe compound formed by a mixture of X and Y will be \(XY_{2}\) not XY. |
|
| 10. |
The electronic configuration of an elements is 1s22s22p63s23p3. How many unpaired electrons are there in the element? A. 5 B. 4 C. 3 D. 2 |
C |