Combined Science practice questions
Chemistry Practice Questions
1. Which of the following cannot reduce iron(III) oxide to iron?
A Coke
B Carbon monoxide
C Carbon
D Limestone
2. Solid Q is insoluble in water. It gives off a gas when heated and also when treated with dilute sulfuric acid. Identify Q.
A Carbon
B Zinc oxide
C Sulfur
D Copper(II) carbonate
3. Which of the following has the most number of electrons?
A Calcium ion
B Fluorine ion
C potassium atom
D Chlorine atom
4. Which of the following properties allows water and ethanol to be separated by distillation?
A They have different densities.
B They have different reactivities.
C They have different mass numbers.
D They have different boiling points.
5. Which of the following sets consists of elements which exist as diatomic molecules at room temperature?
A Nitrogen, oxygen, fluorine
B Hydrogen, oxygen, helium
C Nitrogen, chlorine, neon
D Oxygen, chlorine, helium
6. A metal forms an oxide which dissolves in water. What is the likely pH of the solution formed?
A 2
B 5
C 7
D 11
7. The conversion of ethene into ethanol is an example of _______.
A an addition reaction
B a reduction reaction
C a hydrogenation reaction
D an oxidation reaction
8. Which of the following is the most likely outcome of the reaction between iron and dilute sulfuric acid?
A Iron is reduced.
B Neutralisation occurs.
C A colourless solution is formed.
D A colourless gas is produced.
9. Which of the following are electronic configurations of non-metals?
A 2.5 and 2.7
B 2.1 and 2.8.1
C 2.7 and 2.8.1
D 2.8.3 and 2.4
10. There are 8 protons and 8 neutrons in the nucleus of an atom. Which of the following statements about the atom is false?
A It tends to gain electrons to form an anion.
B It has six valence electrons.
C Its atom has two electrons in the innermost shell.
D It is monatomic.
11. How many moles of water are contained in 4.5 g of water?
A 0.25 mol
B 0.50 mol
C 4.0 mol
D 4.5 mol
12. Which of the following statements about alkanes is correct?
A They can be polymerized.
B They have the same empirical formula.
C They react with dilute acids.
D They are saturated compounds and cannot be oxidized.
13. 12C and 13C are isotopes of carbon.
(a) Explain the meaning of isotopes.
(b) Explain why 12C and 13C have the same chemical properties.
(c) How many neutrons does an atom of 13C have?
14. Sodium nitrate, ammonia, copper(II) sulfate, magnesium carbonate, aluminium oxide.
From the list of compounds above, choose the one that best fits each of the following descriptions.
(a) Contains an ion which is in Group II of the Periodic Table.
(b) Contains a metallic element showing an oxidation number of +3.
(c) Contains both covalent and ionic bonds in the compound.
(d) Has a pH of 11 when dissolved in solution.
Answers:
1. D
2. D
3. C
4. D
5. B
6. D
7. A
8. D
9. A
10. D
11. A
12. D
13(a) Isotopes are atoms of the same element which have the same number of protons but different number of neutrons.
(b) They have the same electronic configuration and the same number of valence electrons.
(c) 13-6=7 neutrons
14(a) magnesium carbonate
(b) aluminium oxide
(c) magnesium carbonate
(d) ammonia
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