311. Arrange the carbanions, $${\left( {C{H_3}} \right)_3}\overline C ,\overline C C{l_3},{\left( {C{H_3}} \right)_2}\overline C H,{C_6}{H_5}\overline C {H_2}$$ in order of their decreasing stability :
A
$${\left( {C{H_3}} \right)_2}\overline C H > \overline C C{l_3} > {C_6}{H_5}\overline C {H_2} > {\left( {C{H_3}} \right)_3}\overline C $$
B
$$\overline C C{l_3} > {C_6}{H_5}\overline C {H_2} > {\left( {C{H_3}} \right)_2}\overline C H > {\left( {C{H_3}} \right)_3}\overline C $$
C
$${\left( {C{H_3}} \right)_3}\overline C > {\left( {C{H_3}} \right)_2}\overline C H > {C_6}{H_5}\overline C {H_2} > \overline C C{l_3}$$
D
$${C_6}{H_5}\overline C {H_2} > \overline C C{l_3} > {\left( {C{H_3}} \right)_3}\overline C > {\left( {C{H_3}} \right)_2}\overline C H$$
Answer :
$$\overline C C{l_3} > {C_6}{H_5}\overline C {H_2} > {\left( {C{H_3}} \right)_2}\overline C H > {\left( {C{H_3}} \right)_3}\overline C $$
312.
$$C{H_3}Br + N{u^ - } \to C{H_3} - Nu + B{r^ - }$$ The decreasing order of the rate of the above reaction with nucleophiles $$\left( {N{u^ - }} \right)$$ A to D is
$$\left[ {N{u^ - } = \left( {\text{A}} \right)Ph{O^ - },\left( {\text{B}} \right)Ac{O^ - },\left( {\text{C}} \right)H{O^ - },\left( {\text{D}} \right)C{H_3}{O^ - }} \right]$$
A
A > B > C > D
B
B > D > C > A
C
D > C > A > B
D
D > C > B > A
Answer :
D > C > A > B
313.
The stability of carbanions in the following
is in the order of
A
(i) > (ii) > (iii) > (iv)
B
(ii) > (iii) > (iv) > (i)
C
(iv) > (ii) > (iii) > (i)
D
(i) > (iii) > (ii) > (iv)
Answer :
(i) > (ii) > (iii) > (iv)
314.
In the given reaction two products are expected.
The product $$(B)$$ is formed as a major product because
A
the carbocation $$C{H_3} - \mathop C\limits^ + H - C{H_3}$$ is formed which is more stable
B
the carbocation $$C{H_3} - C{H_2} - \mathop C\limits^ + {H_2}$$ is formed which is more stable
C
both carbocations are equally stable but the nucleophile attacks on central $$C$$ atom
D
$$C{H_3} - \mathop C\limits^ + H - C{H_3}$$ can easily give a proton to attach $$B{r^ + }.$$
Answer :
the carbocation $$C{H_3} - \mathop C\limits^ + H - C{H_3}$$ is formed which is more stable
315. The products of combustion of an aliphatic thiol $$(RSH)$$ at $$298 K$$ are
A
$$C{o_2}\left( g \right),\,{H_2}O\left( g \right)\,{\text{and}}\,S{O_2}\left( g \right)$$
B
$$C{O_2}\left( g \right),{H_2}O\left( l \right)\,{\text{and}}\,S{O_2}\left( g \right)$$
C
$$C{O_2}\left( l \right),{H_2}O\left( l \right)\,{\text{and}}\,S{O_2}\left( g \right)$$
D
$$C{O_2}\left( g \right),{H_2}O\left( l \right)\,{\text{and}}\,S{O_2}\left( l \right)$$
Answer :
$$C{O_2}\left( g \right),{H_2}O\left( l \right)\,{\text{and}}\,S{O_2}\left( g \right)$$
316. Which of the following represents the given mode of hybridisation $$s{p^2} - s{p^2} - sp - sp$$ from left to right?
A
B
C
D
Answer :
318.
The correct relation between the bond lengths $$a$$ and $$b$$ is :
A
$$a = b$$
B
$$b > a$$
C
$$b < a$$
D
$${\text{Impossible to predict}}$$
Answer :
$$b > a$$
319. In which of the following compounds the carbon marked with asterisk is expected to have greatest positive charge?
A
$$\mathop C\limits^ * {H_3} - C{H_2} - Cl$$
B
$$\mathop C\limits^ * {H_3} - C{H_2} - M{g^ + }C{l^ - }$$
C
$$\mathop C\limits^ * {H_3} - C{H_2} - Br$$
D
$$\mathop C\limits^ * {H_3} - C{H_2} - C{H_3}$$
Answer :
$$\mathop C\limits^ * {H_3} - C{H_2} - Cl$$
320.
How many primary, secondary, tertiary and quaternary carbon atoms are present in the following compound?
A
One primary, two secondary and one tertiary
B
Five primary, three secondary
C
Five primary, one secondary, one tertiary and one quaternary
D
Four primary, two secondary and two quaternary
Answer :
Five primary, one secondary, one tertiary and one quaternary
