Chapter - 1
Chemical Reaction And Equations
( ā§°াāϏাāϝ়āύিāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়া āĻā§°ু āϏāĻŽীāĻā§°āĻŖ )
EXERCISES
( āĻŦ্āϝাāϝ়াāĻŽ )
1. Which of the statements about the reaction below are incorrect?
( āϤāϞ⧰ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻŦিāώāϝ়ে āĻোāύāĻো āĻŽāύ্āϤāĻŦ্āϝ āĻ āĻļুāĻĻ্āϧ? )
2PbO(s) + C(s) → 2Pb(s) + CO₂(g)
(a) Lead is getting reduced.
(āĻ) āϏীāĻš āĻāĻŽি āĻৈ āĻāĻে।
(b) Carbon dioxide is getting oxidised.
(āĻ) āĻাā§°্āĻŦāύ āĻĄাāĻ āĻ āĻ্āϏাāĻāĻĄ āĻ āĻ্āϏিāĻĄাāĻāĻ āĻšৈ āĻৈ āĻāĻে।
(c) Carbon is getting oxidised.
(āĻ) āĻাā§°্āĻŦāύ āĻ āĻ্āϏিāĻĄাāĻāĻ āĻšৈ āĻৈ āĻāĻে।
(d) Lead oxide is getting reduced.
(āĻ) āϏীāĻšā§° āĻ āĻ্āϏাāĻāĻĄ āĻš্ā§°াāϏ āĻĒাāĻāĻে।
(i) (a) and (b)
(i) (āĻ) āĻā§°ু (āĻ)
(ii) (a) and (c)
(ii) (āĻ) āĻā§°ু (āĻ)
(iii) (a), (b) and (c)
(iii) (āĻ), (āĻ) āĻā§°ু (āĻ)
(iv) all
(iv) āϏāĻāϞো
Answer:-
2. Fe2O3 + 2Al2O3 + 2Fe
( āĻĢে⧍āĻā§Š + ⧍āĻāϞ⧍āĻā§Š + ⧍āĻĢে )
The above reaction is an example of a
( āĻāĻĒā§°োāĻ্āϤ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻো āĻāĻা ā§° āĻāĻĻাāĻšā§°āĻŖ )
(a) combination reaction.
(āĻ) āϏংāĻŽিāĻļ্ā§°āĻŖ āĻŦিāĻ্ā§°িāϝ়া।
Answer:-
(b) double displacement reaction.
(āĻ) āĻĻুāĻুāĻŖ āĻŦিāĻ্āϝুāϤি āĻŦিāĻ্ā§°িāϝ়া।
Answer:-
(c) decomposition reaction.
(āĻ) āĻĒāĻāύ āĻŦিāĻ্ā§°িāϝ়া।
Answer:-
(d) displacement reaction.
(āĻ) āĻŦিāĻ্āϝুāϤি āĻŦিāĻ্ā§°িāϝ়া।
Answer:-
3.What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
ā§Š.āϞোāĻšা āĻā§°োā§ąাāϤ āĻĒাāϤāϞ āĻšাāĻāĻĄ্ā§°āĻ্āϞ⧰িāĻ āĻāĻিāĻĄ āϝোāĻ āĻā§°িāϞে āĻি āĻšāϝ়? āϏāĻ িāĻ āĻāϤ্āϤ⧰āϤ āĻিāĻ āĻā§°āĻ।
( āϞোā§° āĻā§°্āϤিāϤ āĻĒাāϤāϞ āĻšাāĻāĻĄ্ā§°āĻ্āϞ'ā§°িāĻ āĻāĻিāĻĄ āϝোāĻ āĻā§°িāϞে āĻি āĻšāϝ়? āϏāĻ িāĻ āĻāϤ্āϤ⧰āĻো āĻিāĻ āĻā§°āĻ। )
(a) Hydrogen gas and iron chloride are produced.
(āĻ) āĻšাāĻāĻĄ্ā§°’āĻেāύ āĻেāĻ āĻā§°ু āĻāĻā§°āĻŖ āĻ্āϞ’ā§°াāĻāĻĄ āĻā§āĻĒāύ্āύ āĻšāϝ়।
(b) Chlorine gas and iron hydroxide are produced.
(āĻ) āĻ্āϞ’ā§°িāύ āĻেāĻ āĻā§°ু āĻāĻā§°āĻŖ āĻšাāĻāĻĄ্ā§°’āĻ্āϏাāĻāĻĄ āĻā§āĻĒāύ্āύ āĻšāϝ়।
(C) No reaction takes place.
(āĻ) āĻোāύো āĻŦিāĻ্ā§°িāϝ়া āύāĻšāϝ়।
(d) Iron salt and water are produced.
(āĻ) āϞোā§° āύিāĻŽāĻ āĻā§°ু āĻĒাāύী āĻā§āĻĒāύ্āύ āĻšāϝ়।
Answer:-
4. What is a balanced chemical equation? Why should chemical equations be balanced ?
( āĻāĻ āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖ āĻি? ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖāĻŦোā§° āĻিāϝ় āϏāύ্āϤুāϞিāϤ āĻā§°িāĻŦ āϞাāĻে? )
Answer:-
5. Translate the following statements into chemical equations and then balance them.
( āύিāĻŽ্āύāϞিāĻিāϤ āĻŽāύ্āϤāĻŦ্āϝāĻŦোā§° ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖāϞৈ āĻ āύুāĻŦাāĻĻ āĻā§°āĻ āĻā§°ু āϤাā§° āĻĒিāĻāϤ āϏেāĻāĻŦোā§° āϏāύ্āϤুāϞিāϤ āĻā§°āĻ। )
(a) Hydrogen gas combines with nitrogen to form ammonia.
(āĻ) āĻšাāĻāĻĄ্ā§°’āĻেāύ āĻেāĻ āύাāĻāĻ্ā§°’āĻেāύ⧰ āϞāĻāϤ āĻŽিāϞি āĻāĻŽোāύিāϝ়া āϏৃāώ্āĻি āĻā§°ে।
Answer:-
(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.
(āĻ) āĻšাāĻāĻĄ্ā§°’āĻেāύ āĻাāϞāĻĢাāĻāĻĄ āĻেāĻ āĻŦাāϝ়ুāϤ āĻ্āĻŦāϞি āĻĒাāύী āĻā§°ু āĻাāϞāĻĢাā§° āĻĄাāĻ āĻ āĻ্āϏাāĻāĻĄ āĻĒোā§ąা āϝাāϝ়।
Answer:-
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(āĻ) āĻŦেā§°িāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄে āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻাāϞāĻĢেāĻā§° āϏৈāϤে āĻŦিāĻ্ā§°িāϝ়া āĻā§°ি āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄ āĻā§°ু āĻŦেā§°িāϝ়াāĻŽ āĻাāϞāĻĢেāĻā§° āĻŦৃāώ্āĻিāĻĒাāϤ āĻĒোā§ąা āϝাāϝ়।
Answer:-
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
(āĻ) āĻĒāĻাāĻিāϝ়াāĻŽ āϧাāϤুā§ąে āĻĒাāύীā§° āϞāĻāϤ āĻŦিāĻ্ā§°িāϝ়া āĻā§°ি āĻĒāĻাāĻিāϝ়াāĻŽ āĻšাāĻāĻĄ্ā§°’āĻ্āϏাāĻāĻĄ āĻā§°ু āĻšাāĻāĻĄ্ā§°’āĻেāύ āĻেāĻ āĻā§āĻĒāύ্āύ āĻā§°ে।
Answer:-
6. Balance the following chemical equations.
( āύিāĻŽ্āύāϞিāĻিāϤ ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖāĻŦোā§° āϏāύ্āϤুāϞিāϤ āĻā§°āĻ। )
(a) HNO, + Ca(OH)₂ → Ca(NO), + H₂O
Answer:-
(b) NaOH + H₂SO → Na₂SO + H₂O
Answer:-
(c) NaCI + AgNO, →→ AgCl + NaNO
Answer:-
(d) BaCl, + H,SO → BaSO + HCI
Answer:-
7. Write the balanced chemical equations for the following reactions.
( āύিāĻŽ্āύāϞিāĻিāϤ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖāĻŦোā§° āϞিāĻāĻ। )
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(āĻ) āĻেāϞāĻিāϝ়াāĻŽ āĻšাāĻāĻĄ্ā§°’āĻ্āϏাāĻāĻĄ + āĻাā§°্āĻŦāύ āĻĄাāĻ āĻ āĻ্āϏাāĻāĻĄ → āĻেāϞāĻিāϝ়াāĻŽ āĻাā§°্āĻŦāύেāĻ + āĻĒাāύী
Answer:-
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(āĻ) āĻিংāĻ + ā§°ূāĻĒাāϞী āύাāĻāĻ্ā§°েāĻ → āĻিংāĻ āύাāĻāĻ্ā§°েāĻ + ā§°ূāĻĒাāϞী
Answer:-
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(āĻ) āĻāϞুāĻŽিāύিāϝ়াāĻŽ + āĻāĻĒাā§° āĻ্āϞ⧰াāĻāĻĄ → āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄ + āĻāĻĒাā§°
Answer:-
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
(āĻ) āĻŦেā§°িāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄ + āĻĒāĻাāĻিāϝ়াāĻŽ āĻাāϞāĻĢেāĻ → āĻŦেā§°িāϝ়াāĻŽ āĻাāϞāĻĢেāĻ + āĻĒāĻাāĻিāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄ
Answer:-
(8) Write the balanced chemical equation for the following and identify the type of reaction in each case.
( āύিāĻŽ্āύāϞিāĻিāϤāĻŦোā§°ā§° āĻŦাāĻŦে āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ āϏāĻŽীāĻā§°āĻŖ āϞিāĻāĻ āĻā§°ু āĻĒ্ā§°āϤিāĻো āĻ্āώেāϤ্ā§°āϤ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻĒ্ā§°āĻাā§° āĻিāύাāĻ্āϤ āĻā§°āĻ। )
(a) Potassium bromide (aq) + Barium iodide(aq) →→→ Potassium iodide (aq) +
(āĻ) āĻĒāĻাāĻিāϝ়াāĻŽ āĻŦ্ā§°āĻŽাāĻāĻĄ (aq) + āĻŦেā§°িāϝ়াāĻŽ āĻāϝ়’āĻĄাāĻāĻĄ(aq) →→→ āĻĒāĻাāĻিāϝ়াāĻŽ āĻāϝ়’āĻĄাāĻāĻĄ (aq) +
Answer:-
(b) Zinc carbonate(s) → Zinc oxide(s) + Carbon dioxide(g)
(āĻ) āĻিংāĻ āĻাā§°্āĻŦāύেāĻ(āϏāĻŽূāĻš) → āĻিংāĻ āĻ āĻ্āϏাāĻāĻĄ(āϏāĻŽূāĻš) + āĻাā§°্āĻŦāύ āĻĄাāĻ āĻ āĻ্āϏাāĻāĻĄ(āĻ)
Answer:-
(c) Hydrogen(g) + Chlorine(g) → Hydrogen chloride(g)
(āĻ) āĻšাāĻāĻĄ্ā§°āĻেāύ(āĻ) + āĻ্āϞ’ā§°িāύ(āĻ) → āĻšাāĻāĻĄ্ā§°’āĻেāύ āĻ্āϞ’ā§°াāĻāĻĄ(āĻ)
Answer:-
(d) Magnesium(s) + Hydrochloric acid(aq) → Magnesium chloride(aq) + Hydrogen(g)
(āĻ) āĻŽেāĻāύেāĻিāϝ়াāĻŽ(āϏāĻŽূāĻš) + āĻšাāĻāĻĄ্ā§°āĻ্āϞ⧰িāĻ āĻāĻিāĻĄ(aq) → āĻŽেāĻāύেāĻিāϝ়াāĻŽ āĻ্āϞ⧰াāĻāĻĄ(aq) + āĻšাāĻāĻĄ্ā§°āĻেāύ(g)
Answer:-
9.What does one mean by exothermic and endothermic reactions? Give examples.
( āĻāĻ্āϏোāĻĨাā§°্āĻŽিāĻ āĻā§°ু āĻāĻŖ্āĻĄোāĻĨাā§°্āĻŽিāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻ ā§°্āĻĨ āĻি? āĻāĻĻাāĻšā§°āĻŖ āĻĻিāϝ়āĻ। )
Answer :-
10. Why is respiration considered an exothermic reaction? Explain.
( āĻļ্āĻŦāϏāύāĻ āĻিāϝ় āĻāĻ āĻāĻ্āĻৃংāĻāϞ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়া āĻŦুāϞি āĻāĻŖ্āϝ āĻā§°া āĻšāϝ়? āĻŦ্āϝাāĻ্āϝা āĻā§°āĻ। )
Answer :-
11.Why are decomposition reactions called the opposite of combination reactions? Write equations for these Reactions.
( āĻĒāĻāύ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻŦোā§°āĻ āϏংāĻŽিāĻļ্ā§°āĻŖ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻŦিāĻĒā§°ীāϤ āĻŦুāϞি āĻিāϝ় āĻোā§ąা āĻšāϝ়? āĻāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāĻŽীāĻā§°āĻŖ āϞিāĻāĻ। )
Answer :-
12. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
( āĻĒāĻāύ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻŦাāĻŦে āĻāĻা āĻৈ āϏāĻŽীāĻā§°āĻŖ āϞিāĻāĻ āϝ'āϤ āϤাāĻĒ, āĻĒোāĻšā§° āĻŦা āĻŦিāĻĻ্āϝুāϤ⧰ ā§°ূāĻĒāϤ āĻļāĻ্āϤি āϝোāĻাāύ āϧ⧰া āĻšāϝ়। )
Answer :-
13. What is the difference between displacement and double displacement reactions? Write equations for these reactions.
( āϏ্āĻĨাāύāĻ্āϝুāϤি āĻā§°ু āĻĻ্āĻŦৈāϤ āϏ্āĻĨাāύাāύ্āϤ⧰ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻŽাāĻāϤ āĻĒাā§°্āĻĨāĻ্āϝ āĻি? āĻāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāĻŽীāĻā§°āĻŖ āϞিāĻāĻ। )
Answer :-
14. In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
( ā§°ূāĻĒā§° āĻļোāϧāύāϤ, ā§°ূāĻĒাāϞী āύাāĻāĻ্ā§°েāĻ āĻĻ্ā§°ā§ąāĻŖā§° āĻĒā§°া ā§°ূāĻĒ āĻĒুāύ⧰ুāĻĻ্āϧাā§°āϤ āϤাāĻŽāϧাāϤুā§° āĻĻ্āĻŦাā§°া āϏ্āĻĨাāύাāύ্āϤ⧰ āĻ āύ্āϤ⧰্āĻুāĻ্āϤ āĻāĻিāϞ। āĻ āύ্āϤ⧰্āĻুāĻ্āϤ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻো āϞিāĻāĻ। )
Answer :-
15. What do you mean by a precipitation reaction? Explain by giving examples.
( āĻŦā§°āώুāĻŖā§° āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াā§° āĻ ā§°্āĻĨ āĻি? āĻāĻĻাāĻšā§°āĻŖ āĻĻি āĻŦā§°্āĻŖāύা āĻā§°āĻ। )
Answer :-
16. Explain the following in terms of gain or loss of oxygen with two examples each.
( āĻĻুāĻা āĻৈ āĻāĻĻাāĻšā§°āĻŖā§° āϏৈāϤে āĻ āĻ্āϏিāĻেāύ āϞাāĻ āĻŦা āĻ্āώāϤিā§° āĻ্āώেāϤ্ā§°āϤ āύিāĻŽ্āύāϞিāĻিāϤāĻŦোā§° āĻŦā§°্āĻŖāύা āĻā§°āĻ। )
(a) Oxidation ( āĻ āĻ্āϏিāĻĄেāĻāύ)
Answer:-
(b) Reduction (āĻāĻŽ āĻā§°āĻŖ)
Answer:-
17. A shiny brown coloured element 'X' on heating in air becomes black in colour. Name the element 'X' and the black coloured compound formed.
( āĻŦāϤাāĻšāϤ āĻā§°āĻŽ āĻā§°াā§° āĻāĻĒā§°āϤ āĻāĻা āĻāĻāĻāĻে āĻŽুāĻা ā§°āĻā§° āĻāĻĒাāĻĻাāύ 'āĻāĻ্āϏ' āĻ'āϞা ā§°āĻā§° āĻšৈ āĻĒā§°ে। 'āĻāĻ্āϏ' āĻāĻĒাāĻĻাāύāĻā§°ু āĻāĻ āύ āĻšোā§ąা āĻ'āϞা ā§°āĻā§° āϝৌāĻāĻোā§° āύাāĻŽ āĻĻিāϝ়āĻ। )
Answer:-
18. Why do we apply paint on iron articles?
( āĻāĻŽি āϞোā§° āϏাāĻŽāĻ্ā§°ীā§° āĻāĻĒā§°āϤ ā§°ং āĻিāϝ় āĻĒ্ā§°āϝ়োāĻ āĻā§°োঁ? )
Answer :-
19. Oil and fat containing food items are flushed with nitrogen. Why?
( āĻাāĻĻ্āϝ āϏাāĻŽāĻ্ā§°ী āĻĨāĻা āϤেāϞ āĻā§°ু āĻā§°্āĻŦি āύাāĻāĻ্ā§°āĻেāύ⧰ āĻĻ্āĻŦাā§°া āĻĢ্āϞাāĻļ āĻā§°া āĻšāϝ়। āĻিāϝ়? )
Answer ;-
20. Explain the following terms with one example each.
( āĻĒ্ā§°āϤিāĻো āĻāĻĻাāĻšā§°āĻŖেā§°ে āύিāĻŽ্āύāϞিāĻিāϤ āĻļāĻŦ্āĻĻāĻŦোā§° āĻŦā§°্āĻŖāύা āĻā§°āĻ। )
(a) Corrosion (āĻাā§°āĻŖ)
Answer:-
(b) Rancidity (ā§°েāύ্āϏিāĻĄিāĻি)
Answer:-
Type by - Pinku Moni bora.
Post ID: DABP001718