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group 1 elements
Here is a 40-mark question paper for Chapter 3 - "Metals and Non-Metals" for Class X Science, featuring a variety of question types including MCQs, 1-mark, 2-mark, 3-mark, 4-mark, and 5-mark questions. The questions are based on previous CBSE exams and focus on some of the more challenging aspects of the chapter.
Metals and Non-Metals - Class X Science
**Time Allowed: 2 Hours**
**Maximum Marks: 40**
#### Section A: Multiple Choice Questions (MCQs) (1 × 5 = 5 Marks)
1. Which of the following metals does not react with dilute hydrochloric acid to produce hydrogen gas?
a. Zinc
b. Iron
c. Copper
d. Aluminium
2. The property of metals by which they can be beaten into thin sheets is called:
a. Ductility
b. Malleability
c. Conductivity
d. Sonority
3. Which of the following pairs will give displacement reactions?
a. NaCl solution and copper metal
b. MgCl₂ solution and aluminium metal
c. FeSO₄ solution and silver metal
d. AgNO₃ solution and copper metal
4. Which of the following is not an alloy?
a. Steel
b. Brass
c. Bronze
d. Graphite
5. Which metal is commonly used for galvanizing iron?
a. Zinc
b. Aluminium
c. Copper
d. Nickel
Section B: Very Short Answer Questions (1 × 3 = 3 Marks)
6. What is the chemical formula for rust?
7. Name the most reactive metal in the reactivity series.
8. Define an alloy.
Section C: Short Answer Questions (2 × 3 = 6 Marks)
9. Explain why ionic compounds have high melting and boiling points.
10. Write the chemical equation for the reaction of iron with steam. Also, write the physical states of all the reactants and products.
11. What happens when a piece of sodium metal is dropped into water? Write the balanced chemical equation for the reaction.
Section D: Short Answer Questions (3 × 3 = 9 Marks)
12. Differentiate between metals and non-metals on the basis of their physical properties. Give any three points.
13. Explain why sodium and potassium are stored in kerosene oil.
14. Describe the steps involved in the extraction of a metal from its ore. Provide a specific example in your explanation.
Section E: Long Answer Questions (4 × 2 = 8 Marks)
15. (a) What are amphoteric oxides? Give two examples of amphoteric oxides.
(b) Explain with the help of a balanced chemical equation how aluminium reacts with both acids and bases.
16. (a) Describe the process of electrolytic refining of copper with a neat labeled diagram.
(b) Why is electrolytic refining used?
Section F: Long Answer Question (5 × 1 = 5 Marks)
17. (a) Discuss the reactivity series of metals.
(b) Explain how the position of a metal in the reactivity series helps in predicting the outcome of its reactions with water, acids, and solutions of other metal salts.
(c) With the help of suitable examples, describe how the reactivity series is useful in predicting the method of extraction of a metal from its ore.
Answer Key:
**Section A:**
1. c. Copper
2. b. Malleability
3. d. AgNO₃ solution and copper metal
4. d. Graphite
5. a. Zinc
**Section B:**
6. Fe₂O₃·nH₂O (Hydrated iron(III) oxide)
7. Potassium
8. An alloy is a mixture of two or more metals, or a metal and a non-metal, which retains the properties of a metal.
**Section C:**
9. Ionic compounds have strong electrostatic forces of attraction between oppositely charged ions, which require a large amount of energy to break, leading to high melting and boiling points.
10. \(\text{3Fe (s) + 4H}_2\text{O (g) → Fe}_3\text{O}_4\text{ (s) + 4H}_2\text{ (g)}\)
11. Sodium reacts vigorously with water to form sodium hydroxide and hydrogen gas:
\(\text{2Na (s) + 2H}_2\text{O (l) → 2NaOH (aq) + H}_2\text{ (g)}\)
**Section D:**
12. Metals are usually hard and have high melting points; non-metals are usually soft and have low melting points. Metals are good conductors of electricity; non-metals are poor conductors. Metals are malleable and ductile; non-metals are brittle and non-ductile.
13. Sodium and potassium are highly reactive and can react vigorously with moisture or oxygen in the air, potentially causing a fire or explosion. They are stored in kerosene oil to prevent such reactions.
14. The extraction of a metal from its ore typically involves the steps of concentration of the ore, reduction of the metal compound to metal, and refining of the metal. For example, in the extraction of iron from its ore (hematite), the ore is first concentrated, then reduced in a blast furnace, and finally refined.
**Section E:**
15. (a) Amphoteric oxides are oxides that can react with both acids and bases to form salt and water. Examples: Aluminium oxide (Al₂O₃) and Zinc oxide (ZnO).
(b) Aluminium reacts with hydrochloric acid to form aluminium chloride and hydrogen gas:
\(\text{2Al (s) + 6HCl (aq) → 2AlCl}_3\text{ (aq) + 3H}_2\text{ (g)}\)
Aluminium reacts with sodium hydroxide to form sodium aluminate and hydrogen gas:
\(\text{2Al (s) + 2NaOH (aq) + 6H}_2\text{O (l) → 2NaAlO}_2\text{ (aq) + 3H}_2\text{ (g)}\)
16. (a) Electrolytic refining of copper involves using an impure copper anode and a pure copper cathode. Copper sulfate solution is used as the electrolyte. When electricity is passed through the solution, pure copper from the anode dissolves into the solution and deposits on the cathode, while impurities settle at the bottom.
(b) Electrolytic refining is used to obtain high-purity metals. It helps in removing impurities from the crude metal.
**Section F:**
17. (a) The reactivity series is a list of metals arranged in order of their decreasing reactivity. It helps in predicting how metals will react with acids, water, and other substances.
(b) Metals higher in the reactivity series react more vigorously with water and acids and can displace metals lower in the series from their salts.
(c) For example, sodium and potassium, being high in the series, react violently with water, whereas iron reacts slowly. In terms of extraction, metals high in the series are extracted by electrolysis (e.g., aluminium), while metals lower in the series can be extracted by reduction with carbon (e.g., iron).
This question paper should help challenge the students and test their understanding of the chapter "Metals and Non-Metals".
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