Metals and Non-Metals
1. Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal (b) MgCl2 solution and aluminum
(c) FeSO4 solution and silver metal (d) AgNO3 solution and copper
2. Which of the following method is suitable for preventing an iron fry pan from rusting?
(a) Applying grease (b) applying paint
(c) Applying coating of zinc (d) All of the above
3. An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be
(a) Calcium (b) Carbon
(c) Silicon (d) iron
4. Food cans are coated with tin and not zinc because
(a) Zinc is costlier than tin (b) Zinc has higher melting point
(c) Zinc is more reactive than tin (d) Zinc is less reactive than tin
5. You are given a hammer, a battery, a bulb, wires and switch.
(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Asses the usefulness of these tests in distinguishing between metals and non-metals?
6. What are amphoteric oxides? Give two examples of amphoteric oxides.
7. Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
8. In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
9. Pratyush took Sulpher powder on spatula and heated it. He collected the gas evolved by inverting a test tube over it as shown in fig. 3.12 below:
(a) What will be the action of gas on
(i) Dry litmus paper? (ii) Moist litmus paper?
(b) Write a balanced chemical equation for the reaction taking place.
10. State two ways to prevent the rusting of iron.
11. What types of oxides are formed when non-metals combine with oxygen?
12. Give reasons:
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminum is highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphides ores are usually converted into oxides during the process of extraction.
13. You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
14. Differentiate between metal and non-metal on the basis of their chemical properties.
15. A man went door to door posing as a goldsmith. He promised to bring back the glitter of the old and dull ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
16. Give reasons, why copper is used to make hot water tanks and not steel (an alloy of iron).
17. Give an example of metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with knife.
(iii) is best conductor of heat.
(iv) is poor conductor of heat.
18. Explain the meaning of malleable and ductile.
19. Why is sodium kept immersed in kerosene oil?
20. Write equation for the reaction of
(i) Iron with steam
(ii) Calcium and potassium with water
21. Samples of four metals A,B,C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows:
Use the table given above to answer the f011owing questions about metals A,B,C and D.
(i) Which is the most reactive metal?
(ii) What would you observe if B is added to a solution of Copper(II) sulphate?
(iii) Arrange the metals A, B,C and D in order of decreasing reactivity.
22. Which gas is produced when dilute hydrochloric acid is added to reactive metal?
23. What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
24. (i) Write the electro-dot structures for sodium, oxygen, and magnesium.
(ii) Show the formation of Na20 and Mg0 by the transfer of electrons.
(iii) What are the ions present in these compounds?
25. Why do ionic compounds have high melting points?
26. Define the following terms:
(i) Minerals (ii) Ores and (iii) Gangue
27. Name two metals which are found in nature in the free state.
28. What chemical process is used for obtaining a metal from its oxide?
29. Metallic oxide of zinc, magnesium and copper were heated with following metals:
In which case will you find displacement reactions taking place?
30. Which metals do not corrode easily?
31. What are alloys?