271.
Given below is a column of adsorbent in which the mixture of compounds $$A + B + C$$ is placed. When the solvent is poured through the column, the components are separated depending upon the degree of adsorption. Which of the given statements is correct?
A
$$A$$ is the most weakly adsorbed component hence remains near the top.
B
$$A$$ is the most strongly adsorbed component hence remains near the top.
C
$$C$$ is the most strongly adsorbed component hence is found near the bottom.
D
$$B$$ is the most strongly adsorbed component hence is found in the centre of the column.
Answer :
$$A$$ is the most strongly adsorbed component hence remains near the top.
272.
Which type of intermediate $$\left( A \right)$$ is formed during the reaction?
$$C{H_3}C{H_2} - N = N - C{H_2}C{H_3}$$ \[\xrightarrow{\text{Heat}}\left( A \right)+{{N}_{2}}\]
A
Carbocation
B
Carbanion
C
Free radical
D
Carbene
Answer :
Free radical
273. Which of the following alkenes is the most stable ?
A
B
C
D
Answer :
274. In Duma's method $$0.52\,g$$ of an organic compound on combustion gave $$68.6\,mL\,{N_2}$$ at $${27^ \circ }C$$ and $$756\,mm$$ pressure. What is the percentage of nitrogen in the compound?
A
$$12.22\% $$
B
$$14.93\% $$
C
$$15.84\% $$
D
$$16.23\% $$
Answer :
$$14.93\% $$
275.
Which of the following resonance structure is lowest in energy ?
A
A
B
B
C
C
D
All have same energy
Answer :
A
276. In $$H{S^ - },{I^ - },RN{H_2},N{H_3}$$ order of proton accepting tendency will be
A
$${I^ - } > N{H_3} > RN{H_2} > H{S^ - }$$
B
$$N{H_3} > RN{H_2} > H{S^ - } > {I^ - }$$
C
$$RN{H_2} > N{H_3} > H{S^ - } > {I^ - }$$
D
$$H{S^ - } > RN{H_2} > N{H_3} > {I^ - }$$
Answer :
$$RN{H_2} > N{H_3} > H{S^ - } > {I^ - }$$
277. The optically active tartaric acid is named as $$D - (+) -$$ tartaric acid because it has a positive
A
optical rotation and is derived from $$D -$$ glucose
B
$$pH$$ in organic solvent
C
optical rotation and is derived from $$D - (+) -$$ glyceraldehyde
D
optical rotation only when substituted by deuterium
Answer :
optical rotation and is derived from $$D - (+) -$$ glyceraldehyde
278. Which one of the following is a free-radical substitution reaction ?
A
B
C
D
Answer :
279. The increasing order of stability of the following free radicals is
A
$${\left( {C{H_3}} \right)_2}\dot CH < {\left( {C{H_3}} \right)_3}\dot C$$ $$ < {\left( {{C_6}{H_5}} \right)_2}\dot CH < {\left( {{C_6}{H_5}} \right)_3}\dot C$$
B
$${\left( {{C_6}{H_5}} \right)_3}\dot C < {\left( {{C_6}{H_5}} \right)_2}\dot CH < $$ $${\left( {C{H_3}} \right)_3}\dot C < {\left( {C{H_3}} \right)_2}\dot CH$$
C
$${\left( {{C_6}{H_5}} \right)_2}\dot CH < {\left( {{C_6}{H_5}} \right)_3}\dot C$$ $$ < {\left( {C{H_3}} \right)_3}\dot C < {\left( {C{H_3}} \right)_2}\dot CH$$
D
$${\left( {C{H_3}} \right)_2}\dot CH < {\left( {C{H_3}} \right)_3}\dot C < $$ $$ {\left( {{C_6}{H_5}} \right)_3}\dot C < {\left( {{C_6}{H_5}} \right)_2}\dot CH$$
Answer :
$${\left( {C{H_3}} \right)_2}\dot CH < {\left( {C{H_3}} \right)_3}\dot C$$ $$ < {\left( {{C_6}{H_5}} \right)_2}\dot CH < {\left( {{C_6}{H_5}} \right)_3}\dot C$$
280.
The IUPAC name for 
is
A
1-chloro- 2-nitro-4- methylbenzene
B
1-chloro-4- methyl- 2-nitrobenzene
C
2-chloro-1-nitro- 5-methylbenzene
D
$$m$$ - nitro - $$p$$ - chlorotoluene
Answer :
1-chloro-4- methyl- 2-nitrobenzene