- No. iv. Give a few uses of ethene.
Answer. Ethene is used:
- For artificial ripening of fruits
- As a general anaesthetic
iii. For manufacture of polythene. Polythene is a plastic material used in packaging, toys, bags.
- As a starting material for the manufacture of a large number of compounds such as ethylene oxide, ethyl alcohol, ethylene glycol, diethyl ether, etc.; ethylene oxide is used as a fumigant, ethylene glycol is used as an anti freeze, and diethyl ether and ethyl alcohol are used as solvents
- For making poisonous mustard gas which is used in chemical warfare.
- No. v. Which gases are present in LPG?
Answer. Propane and butane gases are present in LPG
Test Yourself 12.4 (ALKYNES)
- No. i. Why the alkynes are called acetylenes?
Answer. Alkynes are also called acetylenes because of the name of the first member of the series is acetylene.
- No. ii. How is tetrabromoethane prepared from acetylene?
Answer. When bromine water is added to acetylene, red-brown colour of bromine water is discharged rapidly due to formation of colorless tetrabromoethane.
HC≡CH + 2Br2 → H-C — C-H
- No.iii. How can you prepare acetylene from tetrachloroethane?
Answer. When tetrachloroethane is heated with Zinc dust, the elimination of halogen atoms takes place and acetylene is formed.
Cl Cl heat
H-C―C-H + 2Zn (dust) HC≡CH + 2ZnCl2
- No.iv. What is the difference between glycol and glyoxalin?
Answer. The formula of glycol is:
It is (1,2-ethandiol): It belongs to alcohol family.
The formula of glyoxal is:
It does not belong to alcohol family.
- No. v. Write the formula of oxalic acid
Answer. The formula of oxalic acid is: