Q21 of 23 Page 157

(a) A compound ‘X’ is C2H4. Draw its electron dot structure. Will it dissolve in water or not? Will it conduct electricity in aqueous solution? Will it have high melting or low melting point?

(b) A compound ‘X’ has molecular formula C4H10. It undergoes substitution reaction readily than addition reaction. It burns with blue flame. It is present in LPG. Identify ‘X’ and give the balanced equation for its combustion and substitution reaction with Cl2 in presence of sunlight.


(c) Why are vegetable oils healthy as compared to vegetable ghee? How are vegetable oils converted into vegetable ghee? Name the process.

(a) The electron dot structure of ethene is


Ethene is a non-polar molecule and will not dissolve in water (polar solvent). Since it does not produce ions in water, ethene does not conduct electricity in aqueous solutions. Ethene is a covalent molecule and has low melting point.


(b) The compound X is butane.


Balanced equation for combustion of butane:


2C4H10 + 13O2→ 8CO2 + 10H2O


Substitution reaction with Cl2 in the presence of sunlight:


C4H10 + Cl2→ C4H9Cl + HCl


C4H9Cl + Cl2→ C4H8Cl2 + HCl


The substitution reaction continues until all H is replaced by Cl.


(c) Vegetable oils contain unsaturated carbon chains whereas vegetable ghee contains saturated carbon chains which are said to be harmful to health.


Vegetable oils are converted into vegetable ghee by the process of hydrogenation in the presence of a catalyst like nickel.



More from this chapter

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19

(i) Why do we add ethanol to petrol in these days?

(ii) Give one use of ethanol in medicines.


(iii) Why is vinegar used in pickles?

 20

(a) Identify the compounds ‘A’, ‘B’ and ‘C’ in the following reactions:

(i) C2H5OH + CH3CH2COOH ‘A’ + H2O


(ii) CH3COOC2H5 + NaOH →‘B’ + C2H5OH


(iii) CH3COONa + NaOH(CaO) ‘C’ + Na2CO3


(b) A cyclic compound ‘X’ has molecular formula C6H6. It is unsaturated and burns with a sooty flame. Identify ‘X’ and write its structural formula. Will it decolourise bromine water or not and why?

 22

A prestigious school of Delhi has large canteen which sells burgers, patties, cold drink, Pizzas, Samosas, chips, etc. Most of the children enjoy eating these junk food. School authorities have asked them to sell fresh fruit juices, sprouts, boiled corns, fresh fruits, nimbupani etc. but sale of these items is very less. Some children take sips from same cold drink bottle and bites of same burger.

(a) Which preservative is present in cold drinks?


(b) Which acid is present in vinegar added to vegetable chow mien?


(c) What will you do to make people aware that junk food is harmful for health? Give two suggestions.


(d) What is wrong/right in sipping cold drinks from same bottle or biting same burger by many students? Give one reason.


(e) Do you think junk food and cold drinks should be banned in school canteen as per the directive of Hon’ble High Court’s order? Give two reasons in support of your answer.

 23

Government of India is imposing ban on the use of polythene bags for shopping. List four advantages of using cloth or jute bags over polythene bags.