Chapter 3
Metals and Non-metals
āϧাāϤু āĻā§°ু āĻ -āϧাāϤু
EXERCISES
āĻŦ্āϝাāϝ়াāĻŽ
ā§§. āύিāĻŽ্āύāϞিāĻিāϤ āĻোāύāϝোā§°ে āϏ্āĻĨাāύāĻ্āϝুāϤি ā§°āĻাā§° āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়া āĻĒ্ā§°āĻĻাāύ āĻā§°িāĻŦ?
(a) NaCl solution and copper metal
(āĻ) āĻāύāĻāĻিāĻāϞ āĻĻ্ā§°ā§ąāĻŖ āĻā§°ু āϤাāĻŽāϧাāϤু
(āĻ) āĻāĻŽāĻিāĻিāĻāϞ, āĻĻ্ā§°ā§ąāĻŖ āĻā§°ু āĻāϞুāĻŽিāύিāϝ়াāĻŽ āϧাāϤু
(c) FeSO, solution and silver metal
(āĻ) āĻĢেāĻো, āĻĻ্ā§°ā§ąāĻŖ āĻā§°ু ā§°ূāĻĒাāϞী āϧাāϤু
Ans-
(d) AgNO, solution and copper metal.
(āĻ) āĻāĻিāĻāύāĻ ', āĻĻ্ā§°ā§ąāĻŖ āĻā§°ু āϤাāĻŽāϧাāϤু।
2. Which of the following methods is suitable for preventing an iron frying pan from rusting?
⧍. āϞো āĻĢ্ā§°াāĻং āĻĒেāύ āĻāĻাāĻŽাāĻŽā§°া āĻĒ্ā§°āϤিāĻšāϤ āĻā§°াā§° āĻŦাāĻŦে āύিāĻŽ্āύāϞিāĻিāϤ āĻোāύāĻো āĻĒāĻĻ্āϧāϤি āĻāĻĒāϝুāĻ্āϤ?
(āĻ) āĻ্ā§°ীāĻ āĻĒ্ā§°āϝ়োāĻ āĻā§°া
(b) Applying paint
(āĻ) ā§°ং āĻĒ্ā§°āϝ়োāĻ āĻā§°া
(c) Applying a coating of zinc
(āĻ) āĻিংāĻā§° āĻā§ąā§°āĻŖ āĻĒ্ā§°āϝ়োāĻ āĻā§°া
(d) All of the above.
(āĻ) āĻāĻĒā§°োāĻ্āϤ āϏāĻāϞোāĻŦোā§°।
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
(āĻ) āĻেāϞāĻিāϝ়াāĻŽ
(b) carbon
(āĻ) āĻাā§°্āĻŦāύ
(c) silicon
(āĻ) āĻিāϞিāĻāύ
(d) iron.
(āĻ) āϞো।
4. Food cans are coated with tin and not with zinc because
ā§Ē. āĻাāĻĻ্āϝ⧰ āĻেāύāĻŦোā§° āĻিāύেā§°ে āĻĒ্ā§°āϞেāĻĒ āĻĻিāϝ়া āĻšāϝ় āĻā§°ু āĻিংāĻā§° āϏৈāϤে āύāĻšāϝ় āĻিāϝ়āύো
(a) zinc is costlier than tin.
(āĻ) āĻিংāĻ āĻিāύāϤāĻৈ āĻŦ্āϝāϝ়āĻŦāĻšুāϞ।
(b) zinc has a higher melting point than tin.
(āĻ) āĻিংāĻā§° āĻিāύāϤāĻৈ āĻ āϧিāĻ āĻāϞāύ āĻŦিāύ্āĻĻু āĻĨাāĻে।
(c) zinc is more reactive than tin.
(āĻ) āĻিংāĻ āĻিāύāϤāĻৈ āĻ āϧিāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻļীāϞ।
Ans-
(d) zinc is less reactive than tin.
(āĻ) āĻিংāĻ āĻিāύāϤāĻৈ āĻāĻŽ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻļীāϞ।
5. You are given a hammer, a battery, a bulb, wires and a switch.
ā§Ģ. āĻāĻĒোāύাāĻ āĻāĻা āĻšাāϤুā§°ী, āĻŦেāĻাā§°ী, āĻāĻা āĻŦাāϞ্āĻŦ, āϤাঁā§° āĻā§°ু āĻāĻা āĻুāĻāĻ āĻĻিāϝ়া āĻšৈāĻে।
(āĻ) āϧাāϤু āĻā§°ু āĻ -āϧাāϤুā§° āύāĻŽুāύাā§° āĻŽাāĻāϤ āĻĒাā§°্āĻĨāĻ্āϝ āĻā§°িāĻŦāϞৈ āĻāĻĒুāύি āϏেāĻāĻŦোā§° āĻেāύেāĻĻā§°ে āĻŦ্āĻ¯ā§ąāĻšাā§° āĻā§°িāĻŦ āĻĒাā§°ে?
(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.
(āĻ) āϧাāϤু āĻā§°ু āĻ -āϧাāϤুā§° āĻŽাāĻāϤ āĻĒাā§°্āĻĨāĻ্āϝ āĻā§°াāϤ āĻāĻ āĻĒā§°ীāĻ্āώাāĻŦোā§°ā§° āĻāĻĒāϝোāĻিāϤা āĻŽূāϞ্āϝাāϝ়āύ āĻā§°āĻ।
Ans-
6. What are amphoteric oxides? Give two examples of amphoteric oxides.
ā§Ŧ. āĻāĻŽ্āĻĢোāĻেā§°িāĻ āĻ āĻ্āϏাāĻāĻĄ āĻি? āĻāĻŽ্āĻĢোāĻেā§°িāĻ āĻ āĻ্āϏাāĻāĻĄā§° āĻĻুāĻা āĻāĻĻাāĻšā§°āĻŖ āĻĻিāϝ়āĻ।
7. Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
ā§. āĻĒাāϤāϞ āĻāĻিāĻĄā§° āĻĒā§°া āĻšাāĻāĻĄ্ā§°āĻেāύ āϏ্āĻĨাāύāĻ্āϝুāϤ āĻā§°িāĻŦ āĻĒā§°া āĻĻুāĻা āϧাāϤুā§° āύাāĻŽ āĻĻিāϝ়āĻ, āĻā§°ু āĻĻুāĻা āϧাāϤু āϝি āύāĻā§°ে।
Ans-
8. In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
ā§Ž. āϧাāϤু āĻāĻŽ-ā§° āĻŦৈāĻĻ্āϝুāϤিāĻ āĻļোāϧāύāϤ, āĻāĻĒুāύি āĻāύোāĻĄ, āĻেāĻĨ'āĻĄ āĻā§°ু āĻāϞেāĻ্āĻ্ā§°āϞাāĻāĻ āĻšিāĻাāĻĒে āĻি āϞ'āĻŦ?
Ans-
9. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.
⧝. āĻĒ্ā§°āϤ্āϝুāώে āĻāĻা āϏ্āĻĒাāĻুāϞাāϤ āĻাāϞāĻĢাā§° āĻĒাāĻāĻĄাā§° āϞৈ āĻā§°āĻŽ āĻā§°িāϞে। āϤেāĻঁ āĻāϝ়াā§° āĻāĻĒā§°āϤ āĻāĻা āĻĒā§°ীāĻ্āώা āύāϞী āĻāϞোāĻাāĻ āĻŦিāĻāĻļিāϤ āĻšোā§ąা āĻেāĻāĻো āϏংāĻ্ā§°āĻš āĻā§°িāĻিāϞ, āϤāϞ⧰ āĻিāϤ্ā§°āϤ āĻĻেāĻুāĻā§ąাā§° āĻĻā§°ে।
(a) What will be the action of gas on
(āĻ) āĻেāĻā§° āĻাā§°্āϝ āĻি āĻš'āĻŦ
(āĻ) āĻĄ্ā§°াāĻ āϞিāĻāĻŽাāĻ āĻাāĻāĻ?
(ii) moist litmus paper?
(āĻ) āĻā§°্āĻĻ্ā§° āϞিāĻāĻŽাāĻ āĻাāĻāĻ?
(b) Write a balanced chemical equation for the reaction taking place.
(āĻ) āĻšোā§ąা āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻŦাāĻŦে āĻāĻ āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖ āϞিāĻāĻ।
ā§§ā§Ļ. āϞোā§° āĻŽাāĻŽā§° āĻĒ্ā§°āϤিā§°োāϧ āĻā§°াā§° āĻĻুāĻা āĻāĻĒাāϝ় āĻāϞ্āϞেāĻ āĻā§°āĻ।
11. What type of oxides are formed when non-metals combine with oxygen?
ā§§ā§§. āĻ -āϧাāϤুāĻŦোā§° āĻ āĻ্āϏিāĻেāύ⧰ āϏৈāϤে āĻŽিāĻšāϞি āĻš'āϞে āĻেāύে āϧ⧰āĻŖā§° āĻ āĻ্āϏাāĻāĻĄ āϏৃāώ্āĻি āĻšāϝ়?
12. Give reasons.
⧧⧍. āĻাā§°āĻŖ āĻĻিāϝ়āĻ।
(a) Platinum, gold and silver are used to make jewellery.
(āĻ) āĻāĻšāύা āϤৈāϝ়াā§° āĻā§°িāĻŦāϞৈ āĻĒ্āϞেāĻিāύাāĻŽ, āϏোāĻŖ āĻā§°ু ā§°ূāĻĒ āĻŦ্āĻ¯ā§ąāĻšাā§° āĻā§°া āĻšāϝ়।
(b) Sodium, potassium and lithium are stored under oil.
(āĻ) āĻāĻĄিāϝ়াāĻŽ, āĻĒāĻাāĻিāϝ়াāĻŽ āĻā§°ু āϞিāĻĨিāϝ়াāĻŽ āϤেāϞ⧰ āϤāϞāϤ āϏংā§°āĻ্āώāĻŖ āĻā§°া āĻšāϝ়।
Ans-
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(āĻ) āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻšৈāĻে āĻāĻ āĻ āϤ্āϝাāϧিāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻļীāϞ āϧাāϤু, āϤāĻĨাāĻĒিāĻ āĻāϝ়াāĻ ā§°āύ্āϧাā§° āĻŦাāĻŦে āĻŦাāĻāύ-āĻŦā§°্āϤāύ āϤৈāϝ়াā§° āĻā§°িāĻŦāϞৈ āĻŦ্āĻ¯ā§ąāĻšাā§° āĻā§°া āĻšāϝ়।
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
(āĻ) āύিāώ্āĻাāĻļāύ āĻĒ্ā§°āĻ্ā§°িāϝ়াā§° āϏāĻŽāϝ়āϤ āĻাā§°্āĻŦোāύেāĻ āĻā§°ু āĻাāϞāĻĢাāĻāĻĄ āĻ 'ā§°āĻŦোā§° āϏাāϧাā§°āĻŖāϤে āĻ āĻ্āϏাāĻāĻĄāϞৈ ā§°ূāĻĒাāύ্āϤ⧰িāϤ āĻšāϝ়।
Ans-
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.
ā§§ā§Š. āĻāĻĒুāύি āύিāĻļ্āĻāϝ় āύেāĻŽু āĻŦা āϤাāĻŽোāϞ⧰ ā§°āϏেā§°ে āĻāϞāĻ্āĻিāϤ āϤাāĻŽā§° āĻĒাāϤ্ā§°āĻŦোā§° āĻĒā§°িāώ্āĻাā§° āĻā§°া āĻĻেāĻিāĻে। āĻāĻ āĻেāĻা āĻĒāĻĻাā§°্āĻĨāĻŦোā§° āĻিāϝ় āĻĒাāϤ্ā§°āĻŦোā§° āĻĒā§°িāώ্āĻাā§° āĻā§°াāϤ āĻাā§°্āϝāĻā§°ী āĻšāϝ় āĻŦā§°্āĻŖāύা āĻā§°āĻ।
14. Differentiate between metal and non-metal on the basis of their chemical properties.
ā§§ā§Ē. āϧাāϤু āĻā§°ু āĻ -āϧাāϤুā§° āĻŽাāĻāϤ āϤেāĻঁāϞোāĻā§° ā§°াāϏাāϝ়āύিāĻ āĻুāĻŖাāĻুāĻŖā§° āĻāĻĒā§°āϤ āĻāϧাā§°িāϤ āĻā§°ি āĻĒাā§°্āĻĨāĻ্āϝ āĻā§°āĻ।
15. A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold 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?
ā§§ā§Ģ. āĻāĻāύ āĻŦ্āϝāĻ্āϤিāϝ়ে āĻā§°ে āĻā§°ে āĻৈ āϏোāĻŖোā§ąাāϞ ā§°āĻাā§° āĻĻā§°ে āĻĒোāĻ āĻĻিāĻিāϞ। āϤেāĻঁ āĻĒুā§°āĻŖি āĻā§°ু āύিāϏ্āϤেāĻ āϏোāĻŖā§° āĻ āϞংāĻাā§°ā§° āĻিāϞিāĻি āĻূā§°াāĻ āĻ āύাā§° āĻĒ্ā§°āϤিāĻļ্ā§°ুāϤি āĻĻিāĻিāϞ। āĻāĻā§°াāĻী āĻ āϏāύ্āĻĻিāĻ্āϧ āĻŽāĻšিāϞাāĻ āϤেāĻঁāĻ āϏোāĻŖā§° āĻুāĻĄ়িā§° āĻāĻা āĻেāĻ āĻĻিāĻিāϞ āϝিāĻো āϤেāĻঁ āĻāĻা āύিā§°্āĻĻিāώ্āĻ āϏāĻŽাāϧাāύāϤ āĻĄুāĻŦাāĻ āĻিāϞ। āĻুāĻĄ়িāĻŦোā§° āύāϤুāύ⧰ āĻĻā§°ে āĻিāϞিāĻি āĻāĻ িāĻিāϞ āĻিāύ্āϤু āϏিāĻšঁāϤ⧰ āĻāĻāύ āϝāĻĨেāώ্āĻ āĻš্ā§°াāϏ āĻĒাāĻāĻিāϞ। āĻŽāĻšিāϞাāĻā§°াāĻী āĻŦিāĻāϞিāϤ āĻšৈāĻিāϞ āĻিāύ্āϤু āĻāĻ āύিāώ্āĻĢāϞ āϤ⧰্āĻā§° āĻĒিāĻāϤ āĻŽাāύুāĻšāĻāύে āĻā§°āĻেāĻĻাāĻৈ āĻĒāĻļ্āĻাāĻĻāĻĒāϏ⧰āĻŖ āĻā§°িāĻিāϞ। āϤেāĻঁ āĻŦ্āĻ¯ā§ąāĻšাā§° āĻā§°া āϏāĻŽাāϧাāύ⧰ āĻĒ্ā§°āĻৃāϤি āĻাāύিāĻŦāϞৈ āĻāĻĒুāύি āĻĄিāĻেāĻāĻিāĻā§° āĻূāĻŽিāĻা āĻĒাāϞāύ āĻā§°িāĻŦ āĻĒাā§°িāĻŦāύে?
ā§§ā§Ŧ. Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
16. āϤীāĻা āύāĻšāϝ় āĻā§°āĻŽ āĻĒাāύীā§° āĻেংāĻ āϤৈāϝ়াā§° āĻā§°িāĻŦāϞৈ āϤাāĻŽ āĻিāϝ় āĻŦ্āĻ¯ā§ąāĻšাā§° āĻā§°া āĻšāϝ় āϤাā§° āĻাā§°āĻŖ āĻĻিāϝ়āĻ (āϞোā§° āĻŽিāĻļ্ā§°āĻŖ)।