141. $$p$$ - Nitrophenol is a stronger acid than phenol while $$p$$ - cresol is a weaker acid. This can be explained as
A
$$ - C{H_3}$$ group decreases the electron density on oxygen of $$O-H$$ group making $$p$$ - cresol a weaker acid
B
$$ - N{O_2}$$ group decreases electron density on oxygen of $$O - H$$ group making $$p$$ - nitrophenol a stronger acid
C
$$ - C{H_3}$$ group increases the electron density on oxygen of $$O - H$$ group making release of $${H^ + }$$ easier
D
$$ - N{O_2}$$ group increases the electron density on oxygen of $$O - H$$ group making release of $${H^ + }$$ easier.
Answer :
$$ - N{O_2}$$ group decreases electron density on oxygen of $$O - H$$ group making $$p$$ - nitrophenol a stronger acid
142.
Which are not cleaved by $$HI{O_4}?$$
(i) glycerol
(ii) glycol
(iii) 1, 3 propenediol
(iv) methoxy - 2 - propanol
A
(i), (ii), (iii), (iv)
B
(i), (ii)
C
(ii), (iii)
D
(iii), (iv)
Answer :
(iii), (iv)
143. Among the following the one that gives positive iodoform test upon reaction with $${I_2}$$ and $$NaOH$$ is
A
\[\overset{\begin{smallmatrix}
C{{H}_{3}} \\
|\,\,\,\,\,\,
\end{smallmatrix}}{\mathop{C{{H}_{3}}-CHC{{H}_{2}}OH}}\,\]
B
$$PhCHOHC{H_3}$$
C
$$C{H_3}C{H_2}CH\left( {OH} \right)C{H_2}C{H_3}$$
D
$${C_6}{H_5}C{H_2}C{H_2}OH$$
Answer :
$$PhCHOHC{H_3}$$
144. Out of benzene and phenol, phenol is more easily nitrated because
A
presence of $$-OH$$ group in phenol increases the electron density at $$ortho$$ and $$para$$ - position
B
presence of $$-OH$$ group in phenol decreases the electron density at $$ortho$$ and $$para$$ - position
C
nitration being electrophilic substitution requires less density at $$ortho$$ and $$para$$ - position
D
phenol is more reactive than benzene due to $$-R$$ effect.
Answer :
presence of $$-OH$$ group in phenol increases the electron density at $$ortho$$ and $$para$$ - position
145.
Match the column I with column II and mark the appropriate choice.
| Column I | Column II | ||
|---|---|---|---|
| a. | Methanol | 1. | Ethyl alcohol |
| b. | Fermentation | 2. | Heated copper at 573 $$K$$ |
| c. | Conversion of 2° alcohol to ketone | 3. | Reaction of alkyl halide with sodium alkoxide |
| d. | Williamson's synthesis | 4. | Wood spirit |
A
a - 1, b - 3, c - 2, d - 4
B
a - 2, b - 3, c - 4, d - 1
C
a - 4, b - 1, c - 2, d - 3
D
a - 4, b - 2, c - 3, d - 1
Answer :
a - 4, b - 1, c - 2, d - 3
146. Which of the following statements is correct?
A
The reaction of methyl magnesium iodide with acetone followed by hydrolysis gives secondary butanol.
B
Primary alcohols are dehydrated easily than secondary and tertiary alcohols.
C
Tertiary alcohol is more acidic than primary alcohol.
D
Tertiary butyl alcohol gives turbidity fastest with Lucas reagent.
Answer :
Tertiary butyl alcohol gives turbidity fastest with Lucas reagent.
147.
Consider the following reaction,
\[\text{Ethanol}\xrightarrow{PB{{r}_{3}}}X\xrightarrow{Alc.\,KOH}\] \[Y\xrightarrow[\left( \text{ii} \right)\,{{H}_{2}}O,\,\text{heat}]{\left( \text{i} \right)\,{{H}_{2}}S{{O}_{4}},\,\text{room temperature}}Z\]
The product $$Z$$ is
A
$$C{H_2} = C{H_2}$$
B
$$C{H_3}C{H_2}OC{H_2}C{H_3}$$
C
$$C{H_3}C{H_2}OS{O_3}H$$
D
$$C{H_3}C{H_2}OH$$
Answer :
$$C{H_3}C{H_2}OS{O_3}H$$
148. The compound that will react most readily with $$NaOH$$ to form methanol is
A
$${\left( {C{H_3}} \right)_4}{N^ + }{I^ - }$$
B
$$C{H_3}OC{H_3}$$
C
$${\left( {C{H_3}} \right)_3}{S^ + }{I^ - }$$
D
$${\left( {C{H_3}} \right)_3}CCI$$
Answer :
$${\left( {C{H_3}} \right)_4}{N^ + }{I^ - }$$
149. The most suitable reagent for the conversion of $$RC{H_2}OH \to RCHO$$ is
A
$${K_2}C{r_2}{O_7}$$
B
$$Cr{O_3}$$
C
$$KMn{O_4}$$
D
$$PCC$$
Answer :
$$PCC$$
150.
Consider the following alcohols,
The order of decreasing reactivities of these alcohols towards nucleophilic substitution with $$HBr$$ is :
A
III > I > IV > II
B
III > I > II > IV
C
I > III > IV > II
D
I > III > II > IV
Answer :
III > I > IV > II