Q19 of 38 Page 1

(a) State two main reasons for carbon forming a very large number of compounds.

(b) Give a reason why carbon forms compound


(i) Namely by Covalent bonding


(ii) Having low melting and boiling points


(c) What happens when (Write chemical equations of the reactions)


(i) A piece of sodium metal is added to ethanol.


(ii) Ethanoic acid reacts with sodium hydroxide.

(a) Catenation and tetravalency nature of carbon is the reason for the formation of a large number of compounds.


The property of formation of bonds with other carbon atoms to form long chains of different compounds is called catenation. Carbon has 4 electrons in its outermost orbit so it can either gain 4 electrons or lose 4 electrons to form a bond.


(b) (i) Carbon has 4 electrons in its outermost orbit so it can either gain 4 electrons or lose 4 electrons to form a bond but it is not possible hence it shares electrons with other atoms to form covalent bonds.


(ii) Since carbon form covalent bonds with other atoms and these bonds are weak so they can easily be breakable hence they have low melting and boiling points.


(c) (i) When sodium metal is added to ethanol hydrogen gas is released.


2Na + 2CH3CH2OH → 2CH3CH2ONa + H2


(ii) CH3COOH + NaOH → CH3COONa + H2O


More from this chapter

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17

A child while playing with his father’s spectacles burnt a hole in a piece of them tissue paper by focusing the image of the Sun on at.

(a) Name the defect of vision his father is suffering form.


(b) List two causes of the defect.


(c) Draw a ray diagram to show how this defect may be corrected using a suitable lens.

 18

Some residents of your colony are planning to cut trees to create a place for parking vehicles. You are upset by knowing all this and wanted to do something to create awareness about the importance of trees.

(a) List any three reasons that you will use to convince residents of your colony not to cut the existing trees.


(b) List any three values that would be inculcated amongst them with such approach.

 20

Draw a longitudinal section of a flower and label the following parts –

(a) Part that develops into a fruit


(b) Part that produces pollen grain


(c) Part that transfers male gametes


(d) Part that is sticky to trap.

 20

Write the names of the parts labeled as A, B, C, D in the diagram given below: