tem

The high reactivity of alkyl halides can be explained in tems of nature of C-X bond which is highly polarised covalent bond due to large difference in the electronegativities of carbon and halogen atom. This polarity is responsible for the nucleophilic substitution reaction of alkyl halides which mostly occur by S_(N^(1)) and S_(N^(2)) mechanisms. S_(N^(1)) reaction is a two step process and in the first step R-X ionises to give carbocation (slow process). In the second step the nucleophilic attacks the carbocation from either side to form the prodcut (fast process) . In S_(N^(1)) reaction there can be reacemization and inversion . S_(N^(1)) reaction is favoured by heavy (bulky) groups on the carbon atom attached to halogens. i.e., R_(3)C-Xgt R_(2)CH-Xgt R_CH_(2)X gt CH_(3)X. " In " S_(N^(2)) reaction the strong nucleophilie OH^(-) attacks from the opposite side of the chlorine atom to give an inyermediate (transition state). which breaks to yield the product (alcohol) and leaving (X^(-)) group. The alcohol has a configuration opposite to that of the bromide and is said to proceed with inversion of configuration. S_(N^(2)) reaction is favoured by small groups on the carbon atom attached to halogen i.e., CH_(3)-X gt R-CH_(2)X gt R_(2) CHX gt R_(3) C-X Which of the following is an example of S_(N^(2)) reaction ?

The high reactivity of alkyl halides can be explained in tems of nature of C-X bond which is highly polarised covalent bond due to large difference in the electronegativities of carbon and halogen atom. This polarity is responsible for the nucleophilic substitution reaction of alkyl halides which mostly occur by S_(N^(1)) and S_(N^(2)) mechanisms. S_(N^(1)) reaction is a two step process and in the first step R-X ionises to give carbocation (slow process). In the second step the nucleophilic attacks the carbocation from either side to form the prodcut (fast process) . In S_(N^(1)) reaction there can be reacemization and inversion . S_(N^(1)) reaction is favoured by heavy (bulky) groups on the carbon atom attached to halogens. i.e., R_(3)C-Xgt R_(2)CH-Xgt R_CH_(2)X gt CH_(3)X. " In " S_(N^(2)) reaction the strong nucleophilie OH^(-) attacks from the opposite side of the chlorine atom to give an inyermediate (transition state). which breaks to yield the product (alcohol) and leaving (X^(-)) group. The alcohol has a configuration opposite to that of the bromide and is said to proceed with inversion of configuration. S_(N^(2)) reaction is favoured by small groups on the carbon atom attached to halogen i.e., CH_(3)-X gt R-CH_(2)X gt R_(2) CHX gt R_(3) C-X Which among the following will not give S_(N^(1)) reaction?

The high reactivity of alkyl halides can be explained in tems of nature of C-X bond which is highly polarised covalent bond due to large difference in the electronegativities of carbon and halogen atom. This polarity is responsible for the nucleophilic substitution reaction of alkyl halides which mostly occur by S_(N^(1)) and S_(N^(2)) mechanisms. S_(N^(1)) reaction is a two step process and in the first step R-X ionises to give carbocation (slow process). In the second step the nucleophilic attacks the carbocation from either side to form the prodcut (fast process) . In S_(N^(1)) reaction there can be reacemization and inversion . S_(N^(1)) reaction is favoured by heavy (bulky) groups on the carbon atom attached to halogens. i.e., R_(3)C-Xgt R_(2)CH-Xgt R_CH_(2)X gt CH_(3)X. " In " S_(N^(2)) reaction the strong nucleophilie OH^(-) attacks from the opposite side of the chlorine atom to give an inyermediate (transition state). which breaks to yield the product (alcohol) and leaving (X^(-)) group. The alcohol has a configuration opposite to that of the bromide and is said to proceed with inversion of configuration. S_(N^(2)) reaction is favoured by small groups on the carbon atom attached to halogen i.e., CH_(3)-X gt R-CH_(2)X gt R_(2) CHX gt R_(3) C-X S_(N^(1)) reaction of optically active alkyl halide leads to :

In a sequence of 21 terms the first 11 terms are in A.P.with common difference 2. and the lastterms are in G.P.with common ratio 2. If the middle tem of the A.P.is equal to themiddle term of the G.P.,then the middle term of the entire sequence is

The sum of 'n' terms of an A.P is 715.If first term is incrased by 1, second term is increased by 3, third term is increased by 5 and so on k^(th) term is increased by k^(th) odd integer then sum of 'n' tems is 836 then value of (n/6) is

The sum of 20 terms of a series of which every even term is 2 xx the term before it,every odd term is 3 xx the term before it,the first tem being unity is ((2)/(7))(6^(10)-1) b.((3)/(7))(6^(10)-1) c.((3)/(5))(6^(10)-1) d.none of these