Explore topic-wise InterviewSolutions in .

Blue litmus solution, water, sodium hydrogen carbonate and calcium hydroxide solution

(i) Vegetable oil (like castor oil, cottonseed oil or soyabean oil)

(ii) Sodium hydroxide (caustic soda)

(iii) Sodium chloride (common salt)

B) dehydrating agent, esterification

(a) Both A and R are correct and R explains A.

(a) Soap can be prepared in the laboratory as follows:

1. Take about 20 ml of castor oil (cottonseed oil, linseed oil or soya bean oil) in a beaker.

2. Add 30 ml of 20% sodium hydroxide solution to it.

3. Heat the mixture with constant stirring till a paste of soap is formed.

4. Then add 5 to 10 grams of common salt (sodium chloride).

5. Stir the mixture well and allow it to cool. On cooling the solution, solid soap separates out.

6. When the soap sets, it can be cut into pieces called ‘soap bars’.

(b) Common salt is added to the mixture to make the soap come out of solution. Though most of the soap separates out on its own but some of it remains in solution. Common salt is added to precipitate out all the soap from the aqueous solution.

(c) When soap is used for washing clothes with hard water, a large amount of soap in water is reacting with the calcium and magnesium ions of hard water to form an insoluble precipitate called scum, before it can be used for the real purpose of washing.

Acetic acid – Ethanoic acid 

Propyl alcohol – Propanol

(c) 5% – 8% acetic acid in water

Acetic acid – Ethanoic acid 

Propyl alcohol – Propanol

International Union of Pure & Applied Chemistry

Methylpropane.

Correct option is  D) C₂H₆

Graphene is an allotrope of carbon. Like diamond, and graphite, when subjected to sufficient supply of air, it burns to release carbon dioxide.

Diamond, graphite and fullerene.

Poly Acrylo Nitrile.

The valency of carbon is 4, of all the valencies of carbon, are satisfied, the resultant hydrocarbons are referred to as ‘saturated hydrocarbons’ or alkanes. Their general formula is C_nH_2n+2

(d) All of above

The number of single and double bonds present in benzenes are 9 and 3.

Graphite is commonly used as an abrasive, but diamond is not used. 

The number of neutrons in carbon atoms present in both graphite and diamond are the same. It only depends upon the nature of the element, and both are allotropes of the same element carbon. 

In diamond, each carbon is covalently bonded to 4 other carbon atoms whereas in graphite, each carbon is covalently to 3 other carbon atoms

Difference between diamond and graphite.

Diamond

1. Pure diamond is colorless and transparent.

2. It is the hardest naturally occurring substance.

3. It has high density i.e. 3.5 g/cm³

4. It is bad conduct of electricity.

5. It bums in air at 900°C to form carbon dioxide.

Graphite

1. Graphite is greyish black opaque and shiny.

2. It is soft and greasy to touch.

3. It has low density i.e. 2.39 g / cm³

4. It is good conductor of electricity.

5. It bums in air at 700° C to form carbon dioxide.

PVC is made by polymerization of Vinyl Chloride molecule.

Plastic is polymer of simple organic molecules that can be moulded into solid objects. PVC, polythene, polystyrene, etc. are examples of plastic.

Nomenclature of freon is on the basis of number of carbon, hydrogen and fluorine atoms in molecular formula. 

Example: Freon-xyz Here, 

x = number of carbon atoms-1, 

y = number of hydrogen atoms + 1 

and z = number of fluorine atoms.

Bromine reacts with saturated hydrocarbon at room temperature in the presence of sunlight.

Uses of diamond: It is used for making jewellery, for making cutting instruments for glass and rocks. 

Uses of graphite: It is used for making pencil, as lubricant, etc.

Following are the uses of graphite:

• Used in making pencil.
• Used as dry lubricant.
• For making electrodes.
• For polishing iron articles.
• As moderator in nuclear furnace.

1. Diamond has sp³ hybridisation with tetrahedral environment. As C – C bonds are very strong any attempt to distort the diamond structure requires large amount of energy. Hence diamond is one of the hardest material. 

2. Whereas graphite has sp² hybridisation with layer structure with trigonal planar environment. The layers tend to slide on one another. So graphite is smooth and slippery.

Four features of fullerene:

•  It appears like a football.
• A molecule of fullerene may contain 60, 70 or more atoms of carbon.
• C₆₀(a fullerene) is bad conductor of electricity.
• It acts as superconductor at high temperature.

(c) presence of sunlight

Any carbon atom in diamond is bound to four other carbon atoms results in the strong tetrahedral arrangement. In graphite, a carbon atom is bound to three other carbon atoms. It form hexagonal sheets which are comparatively weakly bonded to each other and thus, they can slip pass to each other. Due to this, diamond is hard but graphite is soft.

Hydrocarbon – Saturated and unsaturated.

It is a compound of hydrogen and carbon..

CNG is lighter than LPG. Hence, in case of leakage CNG goes up in air while LPG spreads on ground. Also CNG has less amount of carbon thus, produce negligible amount of carbon monoxide and carbon dioxide on combustion. Due to this CNG is much better than LPG.

Correct answer is (b) Pentene

Two uses of Freon are: 

(i) As inert solvent. 

(ii) As coolant in refrigerator and cold storage.

When chlorine and fluorine make compounds with carbon, the compounds are called chlorofluorocarbons,.Pqly-chlprp-flupro alkane,is called Freon.

Correct answer is (a) CFCl₃

(b) Isoprene

Cu(3d¹⁰ 4s¹) प्रायः +1 ऑक्सीकरण अवस्था प्रदर्शित करता है तथा Cu+ आयन (3d¹⁰) बनाता है, जिसकी अधिक स्थायी विन्यास होता है।

(d) 3 – Chloro – 1 – propene

(c) Vulcanisation

प्रथम संक्रमण श्रेणी में बायें से दाये जाने पर IE₁ + IE₂ का योग बढ़ता जाता है। इसके परिणामस्वरूप M²⁺ आयन बनाने की प्रवृत्ति घटती जाती है। यही कारण है कि श्रेणी के प्रथम अर्द्ध भाग में +2 अवस्था अधिकाधिक स्थायी होती है।

Correct answer is (b) Prop

Unsaturated Hydrocarbons react with Hydrogen, in presence of catalysts such as palledium or Nickel and forms saturated Hydrocarbons. This is called Hydrogenation of oils.
This process is useful in hydrogenation of oils derived from plants.

(a) (i) C₄H₈ (ii) C₃H₈

(iii) C₃H₄

(b) 14 u

(c) 1 carbon atom and 2 hydrogen atoms i.e. a CH₂ group.

C₂H₂ एवं C₃H₆में योग अभिक्रिया होगी क्योंकि ये असंतृप्त हाईड्रोकार्बन है |

HCl does not contain double bond.

The difference is of 1 carbon and two hydrogen atoms i.e., – CH₂ and mass difference is 14 a.m.u.