Class 10 - Chemistry
Carbon and Its Compounds
(NCERT In Text Activities Solved)
● Make a list of ten things you have used or consumed since the morning.
● Compile this list with the lists made by your classmates and then sort the items into the adjacent Table.
● If there are items which are made up of more than one material, put them into both the relevant columns.
Answer:
(C) -> Indicates carbon-based material.
| Items | Things made of metal | Things made of glass/clay | Others |
|---|---|---|---|
| Spoon, Utensils | Aluminium/Iron | - | |
| Fan | Iron/Aluminium | ||
| Bed, Chair | - | - | Wood (C) |
| Clothes | - | - | Cellulose(C) |
| Toothbrush | - | - | Plastic (C) |
| Tumbler | - | - | - |
| Books | - | - | Wood Pulp, Cellulose (C) |
| Pencils | - | - | Plastic (C) |
| Car | Iron | Glass | Plastic (C) |
| Pencil | Wood (C), Graphite (C) | ||
| Mobile Phones | Glass | Plastic (C), Elctronic Chips(C) |
Observations:
1. Most of the substances contain carbon in it.
Table 4.3
Activity 4.2
● Calculate the difference in the formulae and molecular masses for
(a) CH₃OH and C₂H₅OH
(b) C₂H₅OH and C₃H₇OH, and
(c) C₃H₇OH and C₄H₉OH.
● Is there any similarity in these three?
● Arrange these alcohols in the order of increasing carbon atoms to get a family. Can we call this family a homologous series?
● Generate the homologous series for compounds containing up to four carbons for the other functional groups given in Table 4.3.
Answer:
(a) CH₃OH and C₂H₅OH differ by -CH₂
Mass of CH₃OH = 12 + 1 × 3 + 16 + 1 = 32u
Mass of C₂H₅OH = (12 × 2) + (1 × 5) + 16 + 1 = 46u
Difference → 46 – 32 = 14u
(b) C₂H₅OH and C₃H₇OH differ by -CH₂
Mass of C₂H₅OH = (12 × 2 ) + (1 × 5) + 16 + 1 = 46u
Mass of C₃H₇OH = (12 × 3) + (1 × 7) + 16 + 1 = 60u
Difference → 60 – 46 = 14u
(c) C₃H₇OH and C₄H₉OH differ by -CH₂
Mass of C₃H₇OH = (12 × 3) + (1 × 7) + 16 + 1 = 60u
Mass of C₄H₉OH = 12 × 4) + (1 × 9) + 16 + 1 = 74u
Difference → 74 – 60 = 14u
All 3 groups given above show a similarity i.e. Two consecutive members differ by CH₂ group and mass 14u.
Activity 4.3
✐ CAUTION: This Activity needs the teacher’s assistance.
● Take some carbon compounds (naphthalene,camphor, alcohol) one by one on a spatula and burn
them.
● Observe the nature of the flame and note whether smoke is produced.
● Place a metal plate above the flame. Is there a deposition on the plate in case of any of the compounds?
Answer:
Heating of different carbon compounds, observing the flame and smoke.
| Carbon Compounds | Nature of flame | Deposits on Metal |
|---|---|---|
| Camphor | Smoky flame | Carbon deposits on metal |
| Alcohol | Non-sooty flame | No carbon |
| Acetone | Non-sooty flame | No carbon |
| Naphthalene | Smoky flame | Carbon deposits on metal |
Alcohol and acetone burns with non-sooty flame—complete combustion takes place.
Camphor, naphthalene burns with sooty flame—incomplete combustion takes place.
Camphor, naphthalene burns with sooty flame—incomplete combustion takes place.
