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In order to study the structure, physical properties, chemical properties and biological properties of organic compounds, they must be in the pure state. So organic compounds must be purified.

Four –

(i) CH₃CH₂CHCH₂ 

(ii) CH₃CHCICH₂CI 

(iii) CH₃CICCICH₃ 

(iv) CICH₂ − CH₂ − CH₂CI

C₅H₁₀ :

1. CH₃-CH₂-CH₂-CH = CH₂ (Pent-1-ene) 

2. CH₃ -CH₂ -CH=CH-CH₃ (Pent-2-ene) 

The type of isomerism present above is position isomerism.

(i) N-methylpropan- 1 -amine

(ii) N-methylpropan-2-amine

(iii) N, N-dimethylpropan- 1-amine

In the Lassaigne's test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of ferric ferrocyanide.

6NaCN + FeSO₄ → Na₄[Fe(CN)₆] + Na₂SO₄

3Na₄ [Fe (CN)₆) ] + 2Fe₂(SO₄)₃ → Fe₄ [Fe(CN)₆] + 6Na₂SO₄

In compounds containing nitrogen and Sulphur together, the sodium metal should be in slight excess otherwise in Lassaigne's test, sodium thiocyanate (NaCNS) is formed which gives red colour with Fe³⁺ ions and decomposes follows:

NaSCN + 2Na→ NaCN + Na₂S

3NaSCN + FeCl₃ → Fe(SCN)₃ + 3NaCl

On the basis of above results, it is clear that Ramesh used less sodium and hence NaSCN was formed in the Lassaigne's extract which gave red colouration due to Fe(SCN)₃ formation while Manish and Rajni used excess sodium and hence, NaCN was formed in the Lassaigne's extract which gave Prussian blue colour of Fe₄ [Fe (CN)₆].

In Lassaigne’s test SCN^– ions are formed due to the presence of sulphur and nitrogen both. These give red colour with Fe³⁺ ions. This happens when fusion is not carried out in the excess of sodium. With excess of sodium the thiocyanate ion, if formed, is decomposed as follows:

NaSCN + 2Na ⎯→ NaCN + Na₂S

Electrophiles are attacking reagent that attacks the substrate at high electron density. These are either positively charged species of electron deficient neutral molecules.

e. g. ,H⁺, CI⁺, Br⁺, BF₃ etc

The member of each of the following is:

(a) Saturated Hydrocarbon: Hexane (C₆H₁₄)

(b) Unsaturated Hydrocarbon: Hexene (C₆H₁₂)

To the given gas add few drops of bromine solution in carbon, tetra-chloride. In case of ethene gas, the reddish colour of bromine discharges. However, in case of ethane gas the reddish colour of bromine does not discharge.

They can undergo both substitution as well as addition reactions.

Sodium ethoxide.

functional isomers

(c) -NH₂ : Nitro group

CH₂ = CH − CH = 0 is more stable than CH₂ = CH − O, since the octet of C and O is complete and no separation of opposite charge is there.

White ppt. of Ag₂SO₄ will be formed.

1. Compound with — OH group: Ethanol (C₂H₅OH) 

2. Compound with — COOH group: Ethanoic acid (CH₃COOH) 

3. Homologue of homologous series with G.F. C_nH_2n :Ethene (C₂H₄ )

(c) Many of the organic compounds are inflammable.

1. N, N-dimethylbenzene amine

2. N-ethyl-N-methylpropan-I-amine

Ether only one functional group, prefix is added in nomenclature .

(B)  - CH₂ group

(D) alcohol and ether

Molecular mass is  14 amu

C₂H₅Cl + NaOH(aq) →C₂H₅OH + NaCl.

Substitution reaction. 

(B)  dimethyl ether

On warming the mixture gives fruity smell. 

Enolisation is a process in which keto form is converted into enol form. Both tautomeric forms are equally stable. The less stable form is known as labile form.

Sodium propionate. 

1. Methyl butanol, 

2-Methyl-1-butanol 

2. 2, 2-dimethyl propanol 

3. 2-Bromocyclo pentan- I -ol 

4. 3-Methylbutanal 

5. 3-Methyl-2-butanone

1. Propyne 

2. Pentan-3-ol 

3. 2-Methylpropane 

4. Ethanoic acid 

5. 1,2-Dichloroethane

1. Alkenes, Alkynes and Alkanes 

2. Double, Triple, Single 

3. Ethene, Ethyne, Methene 

4. Addition Substitution

The homologous series of hydrocarbons are:

The correct option is-(b) 2 4 1 3

 d) chromatography

A small piece of dry Sodium metal is heated with a organic compound in a fusion tube for 2 -3 minutes and the red hot tube is plunged in to distilled water contained in a china dish. The contained of the china dish is boiled ,cooled and filtered. The filtrate is known as Sodium fusion extract.

On fusing with sodium metal the elements presents in an organic compounds are converted in to ionic compounds of sodium which are water soluble which can be filtered and detected by the respective tests. 

(ii) Arrow denotes the direction of movement of electrons .

Electrophile and Nucleophile

(B)  Functional group

It arises due to different alkyl chains on either side of the functional group in the molecule. For example, C₄H₁₀O represents methoxypropane (CH₃OC₃H₇) and ethoxyethane (C₂H₅OC₂H₅).

(a) C₆H₅CH₂Cl

C₆H₅CH₂Cl is called benzylchloride.

(i) II and III

(iii) I and IV

(D)   alcohol