Chapter - 1 

Chemical Reaction And Equations

( ā§°াāϏাāϝ়āύিāĻ• āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āφ⧰ু āϏāĻŽীāϕ⧰āĻŖ )


EXERCISES

( āĻŦ্āϝাāϝ়াāĻŽ )

1. Which of the statements about the reaction below are incorrect?

( āϤāϞ⧰ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻŦিāώāϝ়ে āĻ•োāύāϟো āĻŽāύ্āϤāĻŦ্āϝ āĻ…āĻļুāĻĻ্āϧ? )

2PbO(s) + C(s) → 2Pb(s) + CO₂(g) 

(a) Lead is getting reduced.

(āĻ•) āϏীāĻš āĻ•āĻŽি āĻ—ৈ āφāĻ›ে।

(b) Carbon dioxide is getting oxidised.

(āĻ–) āĻ•াā§°্āĻŦāύ āĻĄাāχ āĻ…āĻ•্āϏাāχāĻĄ āĻ…āĻ•্āϏিāĻĄাāχāϜ āĻšৈ āĻ—ৈ āφāĻ›ে।

(c) Carbon is getting oxidised.

(āĻ—) āĻ•াā§°্āĻŦāύ āĻ…āĻ•্āϏিāĻĄাāχāϜ āĻšৈ āĻ—ৈ āφāĻ›ে।

(d) Lead oxide is getting reduced.

(āϘ) āϏীāĻšā§° āĻ…āĻ•্āϏাāχāĻĄ āĻš্ā§°াāϏ āĻĒাāχāĻ›ে।

(i) (a) and (b)

(i) (āĻ•) āφ⧰ু (āĻ–)

(ii) (a) and (c)

(ii) (āĻ•) āφ⧰ু (āĻ—)

(iii) (a), (b) and (c)

(iii) (āĻ•), (āĻ–) āφ⧰ু (āĻ—)

(iv) all

(iv) āϏāĻ•āϞো

Answer:-

2. Fe2O3 + 2Al2O3 + 2Fe

( āĻĢে⧍āĻ“ā§Š + ⧍āĻāϞ⧍āĻ“ā§Š + ⧍āĻĢে )

The above reaction is an example of a

( āĻ“āĻĒā§°োāĻ•্āϤ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāϟো āĻāϟা ā§° āωāĻĻাāĻšā§°āĻŖ )

(a) combination reaction.

(āĻ•) āϏংāĻŽিāĻļ্ā§°āĻŖ āĻŦিāĻ•্ā§°িāϝ়া।

Answer:-

(b) double displacement reaction.

(āĻ–) āĻĻুāĻ—ুāĻŖ āĻŦিāϚ্āϝুāϤি āĻŦিāĻ•্ā§°িāϝ়া।

Answer:-

(c) decomposition reaction.

(āĻ—) āĻĒāϚāύ āĻŦিāĻ•্ā§°িāϝ়া।

Answer:-

(d) displacement reaction.

(āϘ) āĻŦিāϚ্āϝুāϤি āĻŦিāĻ•্ā§°ি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 āĻšাāχāĻĄ্ā§°āĻ•্āϞ⧰িāĻ• āĻāϚিāĻĄ āϝোāĻ— āϕ⧰িāϞে āĻ•ি āĻšāϝ়? āϏāĻ িāĻ• āωāϤ্āϤ⧰āϤ āϟিāĻ• āϕ⧰āĻ•।

( āϞোā§° āĻ­ā§°্āϤিāϤ āĻĒাāϤāϞ āĻšাāχāĻĄ্ā§°āĻ•্āϞ'ā§°িāĻ• āĻāϚিāĻĄ āϝোāĻ— āϕ⧰িāϞে āĻ•ি āĻšāϝ়? āϏāĻ িāĻ• āωāϤ্āϤ⧰āϟো āϟিāĻ• āϕ⧰āĻ•। )

(a) Hydrogen gas and iron chloride are produced.

(āĻ•) āĻšাāχāĻĄ্ā§°’āϜেāύ āĻ—েāĻ› āφ⧰ু āφāχ⧰āĻŖ āĻ•্āϞ’ā§°াāχāĻĄ āĻ‰ā§ŽāĻĒāύ্āύ āĻšāϝ়।

(b) Chlorine gas and iron hydroxide are produced.

(āĻ–) āĻ•্āϞ’ā§°িāύ āĻ—েāĻ› āφ⧰ু āφāχ⧰āĻŖ āĻšাāχāĻĄ্ā§°’āĻ•্āϏাāχāĻĄ āĻ‰ā§ŽāĻĒāύ্āύ āĻšāϝ়।

(C) No reaction takes place.

(āĻ—) āĻ•োāύো āĻŦিāĻ•্ā§°িāϝ়া āύāĻšāϝ়।

(d) Iron salt and water are produced.

(āϘ) āϞোā§° āύিāĻŽāĻ– āφ⧰ু āĻĒাāύী āĻ‰ā§ŽāĻĒāύ্āύ āĻšāϝ়।

Answer:-

4. What is a balanced chemical equation? Why should chemical equations be balanced ?

( āĻāĻ• āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖ āĻ•ি? ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖāĻŦোā§° āĻ•িāϝ় āϏāύ্āϤুāϞিāϤ āϕ⧰িāĻŦ āϞাāĻ—ে? )

Answer:-

5. Translate the following statements into chemical equations and then balance them.

( āύিāĻŽ্āύāϞিāĻ–িāϤ āĻŽāύ্āϤāĻŦ্āϝāĻŦোā§° ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖāϞৈ āĻ…āύুāĻŦাāĻĻ āϕ⧰āĻ• āφ⧰ু āϤাā§° āĻĒিāĻ›āϤ āϏেāχāĻŦোā§° āϏāύ্āϤুāϞিāϤ āϕ⧰āĻ•। )

(a) Hydrogen gas combines with nitrogen to form ammonia.

(āĻ•) āĻšাāχāĻĄ্ā§°’āϜেāύ āĻ—েāĻ› āύাāχāϟ্ā§°’āϜেāύ⧰ āϞāĻ—āϤ āĻŽিāϞি āĻāĻŽোāύিāϝ়া āϏৃāώ্āϟি āϕ⧰ে।

Answer:-

(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.

(āĻ–) āĻšাāχāĻĄ্ā§°’āϜেāύ āĻ›াāϞāĻĢাāχāĻĄ āĻ—েāĻ› āĻŦাāϝ়ুāϤ āϜ্āĻŦāϞি āĻĒাāύী āφ⧰ু āϚাāϞāĻĢাā§° āĻĄাāχ āĻ…āĻ•্āϏাāχāĻĄ āĻĒোā§ąা āϝাāϝ়।

Answer:-

(c)  Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate. 

(āĻ—) āĻŦেā§°িāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄে āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ›াāϞāĻĢেāϟ⧰ āϏৈāϤে āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ি āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄ āφ⧰ু āĻŦেā§°িāϝ়াāĻŽ āĻ›াāϞāĻĢেāϟ⧰ āĻŦৃāώ্āϟিāĻĒাāϤ āĻĒোā§ąা āϝাāϝ়।

Answer:-

(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.

(āϘ) āĻĒāϟাāĻ›িāϝ়াāĻŽ āϧাāϤুā§ąে āĻĒাāύীā§° āϞāĻ—āϤ āĻŦিāĻ•্ā§°িāϝ়া āϕ⧰ি āĻĒāϟাāĻ›িāϝ়াāĻŽ āĻšাāχāĻĄ্ā§°’āĻ•্āϏাāχāĻĄ āφ⧰ু āĻšাāχāĻĄ্ā§°’āϜেāύ āĻ—েāĻ› āĻ‰ā§ŽāĻĒāύ্āύ āϕ⧰ে।

Answer:-

6. Balance the following chemical equations.

( āύিāĻŽ্āύāϞিāĻ–িāϤ ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖāĻŦোā§° āϏāύ্āϤুāϞিāϤ āϕ⧰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.

( āύিāĻŽ্āύāϞিāĻ–িāϤ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖāĻŦোā§° āϞিāĻ–āĻ•। )

(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water

(āĻ•) āĻ•েāϞāϚিāϝ়াāĻŽ āĻšাāχāĻĄ্ā§°’āĻ•্āϏাāχāĻĄ + āĻ•াā§°্āĻŦāύ āĻĄাāχ āĻ…āĻ•্āϏাāχāĻĄ → āĻ•েāϞāϚিāϝ়াāĻŽ āĻ•াā§°্āĻŦāύেāϟ + āĻĒাāύী

Answer:-

(b) Zinc + Silver nitrate → Zinc nitrate + Silver

(āĻ–) āϜিংāĻ• + ā§°ূāĻĒাāϞী āύাāχāϟ্ā§°েāϟ → āϜিংāĻ• āύাāχāϟ্ā§°েāϟ + ā§°ূāĻĒাāϞী

Answer:-

 (c) Aluminium + Copper chloride → Aluminium chloride + Copper

(āĻ—) āĻāϞুāĻŽিāύিāϝ়াāĻŽ + āĻ•āĻĒাā§° āĻ•্āϞ⧰াāχāĻĄ → āĻāϞুāĻŽিāύিāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄ + āĻ•āĻĒাā§°

Answer:-

(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride

(āϘ) āĻŦেā§°িāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄ + āĻĒāϟাāĻ›িāϝ়াāĻŽ āĻ›াāϞāĻĢেāϟ → āĻŦেā§°িāϝ়াāĻŽ āĻ›াāϞāĻĢেāϟ + āĻĒāϟাāĻ›িāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄ

Answer:-

(8) Write the balanced chemical equation for the following and identify the type of reaction in each case.

( āύিāĻŽ্āύāϞিāĻ–িāϤāĻŦোā§°ā§° āĻŦাāĻŦে āϏāύ্āϤুāϞিāϤ ā§°াāϏাāϝ়āύিāĻ• āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ• āφ⧰ু āĻĒ্ā§°āϤিāϟো āĻ•্āώেāϤ্ā§°āϤ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻĒ্ā§°āĻ•াā§° āϚিāύাāĻ•্āϤ āϕ⧰āĻ•। )

(a) Potassium bromide (aq) + Barium iodide(aq) →→→ Potassium iodide (aq) +

(āĻ•) āĻĒāϟাāĻ›িāϝ়াāĻŽ āĻŦ্ā§°āĻŽাāχāĻĄ (aq) + āĻŦেā§°িāϝ়াāĻŽ āφāϝ়’āĻĄাāχāĻĄ(aq) →→→ āĻĒāϟাāĻ›িāϝ়াāĻŽ āφāϝ়’āĻĄাāχāĻĄ (aq) +

Answer:-

(b) Zinc carbonate(s) → Zinc oxide(s) + Carbon dioxide(g)

(āĻ–) āϜিংāĻ• āĻ•াā§°্āĻŦāύেāϟ(āϏāĻŽূāĻš) → āϜিংāĻ• āĻ…āĻ•্āϏাāχāĻĄ(āϏāĻŽূāĻš) + āĻ•াā§°্āĻŦāύ āĻĄাāχ āĻ…āĻ•্āϏাāχāĻĄ(āĻ›)

Answer:-

(c) Hydrogen(g) + Chlorine(g) → Hydrogen chloride(g)

(āĻ—) āĻšাāχāĻĄ্ā§°āϜেāύ(āĻ›) + āĻ•্āϞ’ā§°িāύ(āĻ›) → āĻšাāχāĻĄ্ā§°’āϜেāύ āĻ•্āϞ’ā§°াāχāĻĄ(āĻ›)

Answer:-

 (d) Magnesium(s) + Hydrochloric acid(aq) → Magnesium chloride(aq) + Hydrogen(g)

(āϘ) āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ(āϏāĻŽূāĻš) + āĻšাāχāĻĄ্ā§°āĻ•্āϞ⧰িāĻ• āĻāϚিāĻĄ(aq) → āĻŽেāĻ—āύেāĻ›িāϝ়াāĻŽ āĻ•্āϞ⧰াāχāĻĄ(aq) + āĻšাāχāĻĄ্ā§°āϜেāύ(g)

Answer:-

9.What does one mean by exothermic and endothermic reactions? Give examples.

( āĻāĻ•্āϏোāĻĨাā§°্āĻŽিāĻ• āφ⧰ু āĻāĻŖ্āĻĄোāĻĨাā§°্āĻŽিāĻ• āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻ…ā§°্āĻĨ āĻ•ি? āωāĻĻাāĻšā§°āĻŖ āĻĻিāϝ়āĻ•। )

Answer :-

10.  Why is respiration considered an exothermic reaction? Explain.

( āĻļ্āĻŦāϏāύāĻ• āĻ•িāϝ় āĻāĻ• āωāϚ্āĻ›ৃংāĻ–āϞ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়া āĻŦুāϞি āĻ—āĻŖ্āϝ āϕ⧰া āĻšāϝ়? āĻŦ্āϝাāĻ–্āϝা āϕ⧰āĻ•। )

Answer :-

11.Why are decomposition reactions called the opposite of combination reactions? Write equations for these Reactions.

( āĻĒāϚāύ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāĻŦোā§°āĻ• āϏংāĻŽিāĻļ্ā§°āĻŖ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻŦিāĻĒā§°ীāϤ āĻŦুāϞি āĻ•িāϝ় āĻ•োā§ąা āĻšāϝ়? āĻāχ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ•। )

Answer :-

12. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.

( āĻĒāϚāύ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻŦাāĻŦে āĻāϟা āĻ•ৈ āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ• āϝ'āϤ āϤাāĻĒ, āĻĒোāĻšā§° āĻŦা āĻŦিāĻĻ্āϝুāϤ⧰ ā§°ূāĻĒāϤ āĻļāĻ•্āϤি āϝোāĻ—াāύ āϧ⧰া āĻšāϝ়। )

Answer :-

13. What is the difference between displacement and double displacement reactions? Write equations for these reactions.

( āϏ্āĻĨাāύāϚ্āϝুāϤি āφ⧰ু āĻĻ্āĻŦৈāϤ āϏ্āĻĨাāύাāύ্āϤ⧰ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻŽাāϜāϤ āĻĒাā§°্āĻĨāĻ•্āϝ āĻ•ি? āĻāχ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāĻŦোā§°ā§° āĻŦাāĻŦে āϏāĻŽীāϕ⧰āĻŖ āϞিāĻ–āĻ•। )

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 āύাāχāϟ্ā§°েāϟ āĻĻ্ā§°ā§ąāĻŖā§° āĻĒā§°া ā§°ূāĻĒ āĻĒুāύ⧰ুāĻĻ্āϧাā§°āϤ āϤাāĻŽāϧাāϤুā§° āĻĻ্āĻŦাā§°া āϏ্āĻĨাāύাāύ্āϤ⧰ āĻ…āύ্āϤ⧰্āĻ­ুāĻ•্āϤ āφāĻ›িāϞ। āĻ…āύ্āϤ⧰্āĻ­ুāĻ•্āϤ āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াāϟো āϞিāĻ–āĻ•। )

Answer :-

15. What do you mean by a precipitation reaction? Explain by giving examples.

( āĻŦā§°āώুāĻŖā§° āĻĒ্ā§°āϤিāĻ•্ā§°িāϝ়াā§° āĻ…ā§°্āĻĨ āĻ•ি? āωāĻĻাāĻšā§°āĻŖ āĻĻি āĻŦā§°্āĻŖāύা āϕ⧰āĻ•। )

Answer :-

16. Explain the following in terms of gain or loss of oxygen with two examples each.

( āĻĻুāϟা āĻ•ৈ āωāĻĻাāĻšā§°āĻŖā§° āϏৈāϤে āĻ…āĻ•্āϏিāϜেāύ āϞাāĻ­ āĻŦা āĻ•্āώāϤিā§° āĻ•্āώেāϤ্ā§°āϤ āύিāĻŽ্āύāϞিāĻ–িāϤāĻŦোā§° āĻŦā§°্āĻŖāύা āϕ⧰āĻ•। )

(a) Oxidation  ( āĻ…āĻ•্āϏিāĻĄেāϚāύ)

Answer:-

(b) Reduction (āĻ•āĻŽ āϕ⧰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 āĻ—ā§°āĻŽ āϕ⧰াā§° āĻ“āĻĒā§°āϤ āĻāϟা āϚāĻ•āϚāĻ•ে āĻŽুāĻ—া ā§°āϙ⧰ āωāĻĒাāĻĻাāύ 'āĻāĻ•্āϏ' āĻ•'āϞা ā§°āϙ⧰ āĻšৈ āĻĒā§°ে। 'āĻāĻ•্āϏ' āωāĻĒাāĻĻাāύāφ⧰ু āĻ—āĻ āύ āĻšোā§ąা āĻ•'āϞা ā§°āϙ⧰ āϝৌāĻ—āϟোā§° āύাāĻŽ āĻĻিāϝ়āĻ•। )

Answer:-

18. Why do we apply paint on iron articles?

( āφāĻŽি āϞোā§° āϏাāĻŽāĻ—্ā§°ীā§° āĻ“āĻĒā§°āϤ ā§°ং āĻ•িāϝ় āĻĒ্ā§°āϝ়োāĻ— āϕ⧰োঁ? )

Answer :-

19. Oil and fat containing food items are flushed with nitrogen. Why?

( āĻ–াāĻĻ্āϝ āϏাāĻŽāĻ—্ā§°ী āĻĨāĻ•া āϤেāϞ āφ⧰ু āϚ⧰্āĻŦি āύাāχāϟ্ā§°āϜেāύ⧰ āĻĻ্āĻŦাā§°া āĻĢ্āϞাāĻļ āϕ⧰া āĻšāϝ়। āĻ•িāϝ়? )

Answer ;-

20. Explain the following terms with one example each.

( āĻĒ্ā§°āϤিāϟো āωāĻĻাāĻšā§°āĻŖেā§°ে āύিāĻŽ্āύāϞিāĻ–িāϤ āĻļāĻŦ্āĻĻāĻŦোā§° āĻŦā§°্āĻŖāύা āϕ⧰āĻ•। )

(a) Corrosion  (āϜাā§°āĻŖ)

Answer:-

(b) Rancidity (ā§°েāύ্āϏিāĻĄিāϟি)

Answer:-



Type by - Pinku Moni bora.


Post ID: DABP001718