Page 74 - NCERT Science Class 10 English Medium

4. Draw the structures for the following compounds.
?
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
5. How would you name the following compounds?

(i) CH —CH —Br (ii)
3 2

(iii)

4.3 CHEMICAL PROPERTIES OF CARBON COMPOUNDS

In this section we will be studying about some of the chemical properties
of carbon compounds. Since most of the fuels we use are either carbon
or its compounds, we shall first study combustion.

4.3.1 CombustionCombustion
4.3.1
4.3.1
Combustion
4.3.1 Combustion
4.3.1 Combustion
Carbon, in all its allotropic forms, burns in oxygen to give carbon dioxide
along with the release of heat and light. Most carbon compounds also
release a large amount of heat and light on burning. These are the
oxidation reactions that you learnt about in the first Chapter –
(i) C + O → CO + heat and light
2 2
(ii) CH + O → CO + H O + heat and light
4 2 2 2
(iii) CH CH OH + O → CO + H O + heat and light
3 2 2 2 2
Balance the latter two reactions like you learnt in the first Chapter.
Activity
Activity 4.34.3
Activity 4.3
4.4
Activity
Activity 4.4
Activity 4.4
Activity 4.3 Activity 4.44.4
4.3
Activity
Activity
CAUTION: This Activity needs the teacher’s assistance. n Light a bunsen burner and
n Take some carbon compounds (naphthalene, adjust the air hole at the
camphor, alcohol) one by one on a spatula and burn base to get different types of
them. flames/presence of smoke.
n Observe the nature of the flame and note whether n When do you get a yellow,
smoke is produced. sooty flame?
n When do you get a blue
n Place a metal plate above the flame. Is there a deposition flame?
on the plate in case of any of the compounds?
Saturated hydrocarbons will generally give a clean flame while
unsaturated carbon compounds will give a yellow flame with lots of
black smoke. This results in a sooty deposit on the metal plate in Activity
4.3. However, limiting the supply of air results in incomplete combustion
of even saturated hydrocarbons giving a sooty flame. The gas/kerosene
stove used at home has inlets for air so that a sufficiently oxygen-rich

Carbon and its Compounds 69

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