Chapter 6

Separation of Substances (āĻĻ্ā§°āĻŦ্āϝ⧰ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ)

1. āĻļুāĻĻ্āϧ āωāϤ্āϤ⧰⧰ āĻ—োāϞāϟো āϏāĻŽ্āĻĒূāϰ্āĻŖ āϕ⧰া:

(i) āϤāϞāĻŦ āĻ•োāύāϟো āĻŽিāĻļ্ā§° āĻšাāϤেā§°ে āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি?

āωāϤ্āϤ⧰: (c) āϚাāωāϞ āφ⧰ু āĻļিāϞāĻ—ুāϟি

(ii) āĻĻাāχāϞ āĻŦা āĻŽাāĻš āϧুāĻ“ঁāϤে āĻ•োāύāϟো āĻĒāĻĻ্āϧāϤি āφāĻŽি āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰ো?

āωāϤ্āϤ⧰: (d) āφāϏ্ā§°াā§ąāĻŖ

(iii) āϞো āφ⧰ু āĻ•ā§ŸāϞাā§° āĻ—ু⧜ি āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖā§° āĻŦাāĻŦে āωāĻĒāϝুāĻ•্āϤ āĻĒāĻĻ্āϧāϤি āĻš'āϞ—

āωāϤ্āϤ⧰: (c) āϚুāĻŽ্āĻŦāĻ•ী⧟ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ

(iv) āϚাāĻšā§° āĻĒā§°া āϚাāĻšāĻĒাāϤ āϤāϞ⧰ āĻ•োāύāϟো āĻĒāĻĻ্āϧāϤিā§°ে āĻĒৃāĻĨāĻ• āϕ⧰া āĻšā§Ÿ?

āωāϤ্āϤ⧰: (d) āĻĒā§°িāϏ্āϰাāĻŦāĻŖ

2. āϤāϞāϤ āĻĻি⧟াāĻŦোā§° āĻŽিāϞোā§ąা –

                       Column A (āĻĒāĻĻ)                                   Column B (āωāĻĒāϝুāĻ•্āϤ āĻŽিāϞ)

                        (a) āĻĒাāύীāϤ āĻĨāĻ•া āĻŦোāĻ•া                           (ii) āϜ⧰া āĻŦা 'āĻŦাঁ' āĻĻি⧟া

                        (b) āĻŦোāĻ•া āĻĒাāύীāϤ āĻĨāĻ•া āĻĢিāϟ⧰ুāĻ•িāĻŦি           (iv) āĻĒā§°িāϏ্āϰাāĻŦāĻŖ

                        (c) āωāϚ্āϚ āĻŦেāĻ—āϤ āĻŽিāĻļ্āϰāϟো āϘুā§°োā§ąা                 (v) āĻŽāĻ āύ

                        (d) āĻŦাāĻĻাāĻŽā§° āϤেāϞ āφ⧰ু āĻĒাāύী                   (vi) āφāϏ্ā§°াā§ąāĻŖ

                        (e) āĻŦাāϞি āφ⧰ু āϞোā§° āĻ—ু⧜ি                   (i) āϚুāĻŽ্āĻŦāĻ•ী⧟ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ

                        (f) āĻĒাāύীāϤ āĻĻ্āϰāĻŦীāĻ­ূāϤ āύিāĻŽāĻ–                  (vii) āĻŦাāώ্āĻĒীāĻ­āĻŦāύ

                        (g) āϚাāωāϞāϤ āĻĨāĻ•া āϤুঁāĻš                          (iii) āĻĒā§°্āϝ⧰ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ

3. āĻ–াāϞী āĻ াāχ āĻĒূā§° āϕ⧰া:

(a) āϜাā§ąāĻŦā§° āĻĻ'āĻŽā§° āĻĒā§°া āϞোā§° āϟুāĻ•ুā§°া āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦāϞৈ ----------------------āĻšā§Ÿ। 

āωāϤ্āϤ⧰:  āϚুāĻŽ্āĻŦāĻ•ী⧟ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ

(b) āĻĻুāϟা āĻŽিāĻšāϞি āύোāĻšোā§ąা āϜুāϞী⧟া āĻĻ্āϰāĻŦ্āϝ---------------āĻĒāĻĻ্āϧāϤি āĻŦ্āĻ¯ā§ąāĻšাāĻŦ āϕ⧰া āĻĒāĻĻ্āϧāϤিā§° āϏāĻšা⧟āϤ āĻĒৃāĻĨāĻ• āĻ•āĻŦিāĻŦ āĻĒাāĻŦি। 

āωāϤ্āϤ⧰: āφāϏ্āϰাāĻŦāĻŖ 

(c) āφāϟা āφ⧰ু āϤুāĻš ------------ āĻĒāĻĻ্āϧāϤিā§°ে āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি।

āωāϤ্āϤ⧰: āϚাāϞāύীā§°ে āϚāϞা

(d) ------------------- āĻĒāĻĻ্āϧāϤিā§°ে āĻ–েā§°ā§° āĻĒā§°া āϘেঁāĻšু āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি।

āωāϤ্āϤ⧰: āϜ⧰া āĻŦা āĻŦাঁ āĻĻি⧟া

(e) āĻŦাāϞি-āĻĒাāύীā§° āĻŽিāĻļ্āϰ āĻāϟাā§° āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ āϕ⧰োঁāϤে, āĻĒাāύীā§° āĻ•āĻŖিāĻ•াāĻŦোā§° āĻĢিāϞ্āϟাā§° āĻ•াāĻ—āϜ⧰ āĻ›িāĻĻ্āϰāĻŦোā§°ā§° āĻŽাāϜেāĻĻি āϏ⧰āĻ•ি āϝা⧟ āĻ•াā§°āĻŖ āĻĒাāύীā§° āĻ•āĻŖিāĻ•াāĻŦোā§° ------------- āφ⧰ু ------------- āĻŦাāϞিā§° āĻ•āĻŖিāĻ•াāĻŦোā§° --------------।

āωāϤ্āϤ⧰: āϏ⧰ু , āĻĻ্ā§°ā§ąীāĻ­ূāϤ,

4. āϤāϞ⧰ āĻĒ্ā§°āĻļ্āύāĻŦোā§°ā§° āωāϤ্āϤ⧰:

(a) āύিāĻŽāĻ– āφ⧰ু āĻŦাāϞিā§° āĻŽিāĻļ্ā§° āĻ•িāĻĻā§°ে āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦা?

āωāϤ্āϤ⧰: āĻŽিāĻļ্ā§°āĻŖāϟো āĻĒাāύীāϤ āĻĒেāϞাāϞে āύিāĻŽāĻ– āĻ—āϞি āϝা⧟ āφ⧰ু āĻŦাāϞি āϤāϞāϤ āĻĨি⧟ে āĻĨাāĻ•ে। āϤাā§°āĻĒā§°া āĻĢিāϞ্āϟাā§° āϕ⧰ি āύিāĻŽāĻ– āĻĒাāύীā§° āĻĒā§°া āĻŦাāϞি āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি āφ⧰ু āϤাā§°āĻĒā§°া āĻŦাāώ্āĻĒীāĻ­āĻŦāύ āĻĻ্āĻŦাā§°া āύিāĻŽāĻ– āωāϞি⧟াāĻŦ āĻĒাā§°ি।

(b) āύাā§°িāĻ•āϞ āϤেāϞ āφ⧰ু āĻĒাāύীā§° āĻŽিāĻļ্ā§° āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖā§° āĻŦাāĻŦে āĻāϟা āĻĒāĻĻ্āϧāϤি āφāĻ—āĻŦā§োā§ąা।

āωāϤ্āϤ⧰: āĻāχ āĻĻুāχāϟাā§°ে āϘāύāϤ্āĻŦ āĻ­িāύ্āύ। āϏে⧟ে āφāϏ্āϰাāĻŦāĻŖ āĻĒāĻĻ্āϧāϤি āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰ি āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি।

(c) āύিāĻŽāĻ– āĻĒাāύীā§° āĻĒā§°া āύিāĻŽāĻ– āĻ•েāύেāĻĻā§°ে āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦা?

āωāϤ্āϤ⧰: āύিāĻŽāĻ– āĻĒাāύীāϤ āĻĻ্āϰāĻŦীāĻ­ূāϤ āĻšৈ āĻĨাāĻ•ে, āϏে⧟ে āĻŦাāώ্āĻĒীāĻ­āĻŦāύ āĻĒāĻĻ্āϧāϤিā§°ে āĻĒাāύী āω⧰াāχ āĻĒেāϞাāϞে āύিāĻŽāĻ– āĻĒৃāĻĨāĻ• āĻšৈ āĻĨাāĻ•ে।

5. āϤāϞ⧰ āĻŽিāĻļ্ā§°āĻŦোā§°āϤ āωāĻĒাāĻĻাāύāĻŦোā§°ā§° āĻ•ি āϧ⧰্āĻŽā§° āĻŦাāĻŦে āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি?

(a) āύিāĻŽāĻ– āφ⧰ু āϚāϕ⧰ āĻ—ু⧜ি – āύিāĻŽāĻ– āĻĒাāύীāϤ āĻ—āϞে, āϚāϕ⧰ āĻ—ু⧜ি āĻ—āϞ āύাāϝা⧟।

(b) āϧাāύ āφ⧰ু āĻ–েā§° – āĻ–েā§° āĻĒাāϤāϞ, āϧাāύ āĻ“āϜāύ, āϏে⧟ে āϜ⧰া āĻŦা āĻŦাঁ āĻĻি⧟া।

(c) āϚāĻ• āφ⧰ু āĻ•ā§ŸāϞা – āφāĻ•াā§° āĻŦা āϘāύāϤ্āĻŦā§° āĻ­িāύ্āύāϤা।

(d) āϞোā§° āϟুāĻ•ুā§°া āφ⧰ু āĻ•াāĻ ā§° āĻ—ু⧜ি – āϞো āϚুāĻŽ্āĻŦāĻ•ে āφāϕ⧰্āώāĻŖ āϕ⧰ে, āĻ•াāĻ  āύāĻšā§Ÿ।

(e) āĻŦাāϞি āφ⧰ু āϚাāωāϞ – āφāĻ•াā§°ā§° āĻ­িāύ্āύāϤা; āϚাāϞāύীā§°ে āϚāϞাāχ āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āĻĒাā§°ি।

6. āϏাāĻ—ā§°ā§° āĻĒাāύীā§° āĻĒā§°া āύিāĻŽāĻ– āĻ•েāύেāĻĻā§°ে āφāĻšā§°āĻŖ āϕ⧰া āĻšā§Ÿ?

āωāϤ্āϤ⧰: āϏাāĻ—ā§°ā§° āĻĒাāύী āĻāϟি āĻĢ্āϞাāϟ āĻŽাāϟিāϤ āĻĒেāϞাāχ āĻĻিāϞে āĻĒাāύী āĻŦাāώ্āĻĒ āĻšৈ āω⧰ি āϝা⧟। āĻŦাāĻ•ি āĻĨāĻ•া āύিāĻŽāĻ–āϟো āĻļুāĻ•াāχ āωāĻ ি āϏংāĻ—্ā§°āĻš āϕ⧰া āĻšā§Ÿ — āĻāχ āĻĒāĻĻ্āϧāϤিāĻ• āĻŦাāώ্āĻĒীāĻ­āĻŦāύ āĻŦোāϞে।

7. āĻŽিāĻļ্ā§° āĻāϟাā§° āĻĒā§°া āωāĻĒাāĻĻাāύāĻŦোā§° āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦāϞৈ āωāĻĒāϝুāĻ•্āϤ āĻĒāĻĻ্āϧāϤি āĻ•িāĻĻā§°ে āύিā§°্āϧাā§°āĻŖ āϕ⧰া āĻšā§Ÿ?

āωāϤ্āϤ⧰: āωāĻĒাāĻĻাāύāĻŦোā§°ā§° āĻĻৈāĻšিāĻ• āĻ—ুāĻŖ (āϝেāĻŽāύ: āφāĻ•াā§°, āϘāύāϤ্āĻŦ, āϚুāĻŽ্āĻŦāĻ•ী⧟āϤা, āĻĻ্āϰāĻŦāĻŖāĻ•্āώāĻŽāϤা, āφāĻ া, āχāϤ্āϝাāĻĻি) āĻ…āύুāϏ⧰ি āύিā§°্āϧাā§°āĻŖ āϕ⧰া āĻšā§Ÿ।

8. āύāĻĻীā§° āĻŦোāĻ•া āĻĒাāύীā§° āĻĒā§°া āĻĢāϟāĻĢāϟী⧟া āĻĒাāύী āĻĒাāĻŦā§° āĻŦাāĻŦে āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰িāĻŦ āĻĒā§°া āĻĒāĻĻ্āϧāϤিāϏāĻŽূāĻš:

āωāϤ্āϤ⧰: āĻŦাঁ āĻĻি⧟া (Sedimentation)

        āĻĒā§°িāϏ্ā§°াāĻŦāĻŖ (Filtration)

        āĻŽāĻ āύ (Centrifugation)

        āϜ⧰া āĻĻি⧟া (Decantation)

9. āωāĻĒāϝুāĻ•্āϤ āϚিāϤ্ā§°āϏāĻš āĻĒā§°িāϏ্ā§°াāĻŦāĻŖ āĻĒāĻĻ্āϧāϤি āĻŦ্āϝাāĻ–্āϝা āϕ⧰া (āωāϞ্āϞেāĻ–):

āωāϤ্āϤ⧰: āĻĒā§°িāϏ্ā§°াāĻŦāĻŖāϤ, āĻŽিāĻļ্ā§°āϟো āĻāĻ–āύ āĻĢিāϞ্āϟাā§° āĻ•াāĻ—āϜ āĻŦা āĻ…āύ্āϝ āĻāĻ• āĻ›িāĻĻ্ā§°āϝুāĻ•্āϤ āĻŦāϏ্āϤুā§° āĻ“āĻĒā§°āϤ āĻĒেāϞোā§ąা āĻšā§Ÿ। āϝি āĻĒāĻĻাā§°্āĻĨāĻŦোā§° āĻ—āϞি āĻĨাāĻ•ে āĻŦা āϏ⧰ু āĻ•āĻŖিāĻ•াā§° āĻšā§Ÿ, āϏে⧟া āϤāϞāϤ āĻĒā§°ে (āĻĢিāϞ্āϟ্ā§°েāϟ)। āφ⧰ু āϝিāĻŦোā§° āĻĄাāϙ⧰ āĻ•āĻŖিāĻ•াā§°, āϏে⧟া āĻ“āĻĒā§°āϤ āĻĨাāĻ•ে (āĻ†ā§ąā§°োāϧ)।

(🔹 āϚিāϤ্ā§° āϝোāĻ—াāĻŦ āϞাāĻ—ে - āĻĢিāϞ্āϟাā§° āĻĒেāĻĒাā§°, āĻŦীāĻ•াā§°, āĻĢাāύেāϞ āφāĻĻি āĻĻেāĻ–ুā§ąাāχ)

10. āĻĒাāĻ ā§° āĻ•্āϰি⧟া-āĻ•āϞাāĻĒ 6.2 āĻ…āύুāϏ⧰ি, āϏāĻŽ্āĻ­ā§ąāĻĒā§° āĻŽিāĻļ্ā§°āĻŦোā§°ā§° āωāĻĒāϝুāĻ•্āϤ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ āĻĒāĻĻ্āϧāϤিāϏāĻŽূāĻš:

                    āĻŽিāĻļ্ā§° āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ               āĻĒāĻĻ্āϧāϤি

                    āĻŦাāϞি āφ⧰ু āĻĒাāύী                    āĻĒā§°িāϏ্ā§°াāĻŦāĻŖ

                    āύিāĻŽāĻ– āφ⧰ু āĻĒাāύী            āĻŦাāώ্āĻĒীāĻ­āĻŦāύ

                    āϤেāϞ āφ⧰ু āĻĒাāύী                    āφāϏ্āϰাāĻŦāĻŖ

                    āϧাāύ āφ⧰ু                               āĻ–েā§° āϜ⧰া

                    āϚাāωāϞ āφ⧰ু āĻļিāϞāĻ—ুāϟি            āĻšাāϤেā§°ে āĻŦāϚা

                    āĻ•ā§ŸāϞা āφ⧰ু āϞো                    āϚুāĻŽ্āĻŦāĻ•ী⧟ āĻĒৃāĻĨāĻ•ীāϕ⧰āĻŖ

āĻ…āϤিā§°িāĻ•্āϤ āĻĒ্ā§°āĻļ্āύ āφ⧰ু āωāϤ্āϤ⧰:

Q1. āĻ•ি⧟  āĻŽিāĻļ্ā§°āĻŦোā§° āĻĒৃāĻĨāĻ• āϕ⧰িāĻŦ āϞাāĻ—ে?

āωāϤ্āϤ⧰: āĻ•িāĻ›ুāĻŽাāύ āĻŽিāĻļ্ā§° āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰িāĻŦāϞে āωāĻĒāϝোāĻ—ী āύāĻšā§Ÿ āĻŦা āωāĻĒাāĻĻাāύāĻŦোā§° āĻŦেāϞেāĻ— āĻŦেāϞেāĻ— āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰িāĻŦ āϞাāĻ—ে, āϏেāχāĻŦাāĻŦে āĻĒৃāĻĨāĻ• āϕ⧰া āĻšā§Ÿ।

Q2. āĻĒā§°িāϏ্ā§°াāĻŦāĻŖāϤ āĻ•েāύেāϧ⧰āĻŖā§° āĻĒāĻĻাā§°্āĻĨ āĻŦেāϞেāĻ— āϕ⧰া āĻšā§Ÿ?

āωāϤ্āϤ⧰: āĻĒā§°িāϏ্ā§°াāĻŦāĻŖāϤ āĻĻ্ā§°āĻŦāĻŖ āφ⧰ু āĻ•āĻ িāύ āĻĒāĻĻাā§°্āĻĨā§° āĻŽিāĻļ্ā§° āĻĒৃāĻĨāĻ• āϕ⧰া āĻšā§Ÿ āϝ'āϤ āĻ•āĻ িāύāĻŦোā§° āĻĒাāύীāϤ āĻ—āϞি āύাāϝা⧟।

Q3. āĻŽāĻ āύ āĻ•েāϤি⧟া āĻŦ্āĻ¯ā§ąāĻšাā§° āϕ⧰া āĻšā§Ÿ?

āωāϤ্āϤ⧰: āϝেāϤি⧟া āωāĻĒাāĻĻাāύāĻŦোā§°āĻ• āωāϚ্āϚ āĻŦেāĻ—āϤ āϘূā§°াāχ āĻ…āϧিāĻ• āĻ—ুā§°ি āĻĨāĻ•া āĻŦāϏ্āϤু āφঁāϤ⧰াāĻŦ āϞাāĻ—ে।


OLD

Changes around us

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Exercises (āĻ…āύুāĻļীāϞāύী)

1.    To walk through a waterlogged area, you usually shorten the length of your dress by folding            it. Can this change be reversed?

Ans:- We can reverse this change. We can bring the stranded water back to where it used to be.


2.    You accidentally dropped your favourite toy and broke it. This is a change you did not want.        Can this change be reversed?

Ans:- This change is not a reversible change.


3.    Some changes are listed in the following table. For each change, write in the blank column,           whether the change can be reversed or not.


S. No. Change Can be reversed (Yes/No)
1 The sawing of a piece of wood
2 The melting of ice candy
3 Dissolving sugar in water
4 The cooking of food
5 The ripening of a mango
6 Souring of milk

4.    A drawing sheet changes when you draw a picture on it. Can you reverse this change?

Ans:- This change can be reversed. This is because a rubber can be erased and reversed.

5.    Give examples to explain the difference between changes that can or cannot be reversed.

Ans:- The difference between changes that can be reversible and cannot be counterproductive is-               Things that have changed in the change that can be reversed can be brought back to their previous form.

    For example, after preparing a boat with paper, the paper can be returned to its original form.    

    On the other hand, things that have been changed in the change that cannot be reversed cannot be returned to the previous form.

    For example- after being caught in iron, it cannot be returned to the previous form. 

        

6.    A thick coating of a paste of Plaster of Paris (POP) is apploed over the bandage on a                       fractured bone. it becomes hard on drying to keep the fractured bone immobilised. Can The        change in POP be reversed?

Ans:-  The plaster of paris, which is coated on the bandage of broken bones, becomes harder to dry and keeps the fractured bone unable to move. This change in plaster of paris cannot be reversed.

7.    A bag of cement lying in the open gets wet due to rain during the night. The next day the sun        shines brightly. Do you think the changes, which have occurred in the cement, could be                   reversed?

Ans:-   Can't, because even if the cement sack is dry well, the cement sack is no longer as good as before. 


 


Answer by - Sourabh Bora