The acidic hydrolysis of ether $(X)$ shown below is fastest when
- one phenyl group is replaced by a methyl group
- one phenyl group is replaced by a para-methoxyphenyl group
- two phenyl groups are replaced by two para-methoxyphenyl groups
- no structural change is made to X
The Correct Option is C
Solution and Explanation
Top Questions on Ethers
- Williamson’s synthesis of preparing dimethyl ether is a/an:
- Replacement of a hydrogen atom in a hydrocarbon by an alkoxy or carboxyl group yields a class of compounds known as ethers. Ethers are classified as symmetrical or unsymmetrical on the basis of groups attached to the oxygen atoms. Diethyl ether, a symmetrical ether, has been widely used as an inhalation anesthetic. Ethers can be prepared by acid catalyzed intermolecular dehydration of alcohols and Williamson's synthesis. Acid catalyzed dehydration of alcohols is not generally preferred as it gives a mixture of elimination and substitution products. In Williamson's synthesis, an alkyl halide is allowed to react with sodium alkoxide. Ethers containing substituted Alkyl groups may also be prepared by this method. The C-O bond in ether is weakly polar and is cleaved under drastic conditions with excess of hydrogen halides. In electrophilic substitution, the alkoxy group deactivates the aromatic ring and directs the incoming group to ortho and para positions.
- What happens when C₆H₅–O–R is treated with HX?
- Which of the following reagents is required for the conversion of Benzene to methyl benzoate?
(A) Br\(_2\)/FeBr\(_3\)
(B) Mg, dry Ether
(C) CO\(_2\), H\(_3\)O\(^+\)
(D) Methanol, Conc. H\(_2\)SO\(_4\) - Identify the dimethyl ether.
Questions Asked in JEE Advanced exam
- Consider the vectors $$ \vec{x} = \hat{i} + 2\hat{j} + 3\hat{k},\quad \vec{y} = 2\hat{i} + 3\hat{j} + \hat{k},\quad \vec{z} = 3\hat{i} + \hat{j} + 2\hat{k}. $$ For two distinct positive real numbers $ \alpha $ and $ \beta $, define $$ \vec{X} = \alpha \vec{x} + \beta \vec{y} - \vec{z},\quad \vec{Y} = \alpha \vec{y} + \beta \vec{z} - \vec{x},\quad \vec{Z} = \alpha \vec{z} + \beta \vec{x} - \vec{y}. $$ If the vectors $ \vec{X}, \vec{Y}, \vec{Z} $ lie in a plane, then the value of $ \alpha + \beta - 3 $ is ________.
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
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(Here, the inverse trigonometric functions $ \sin^{-1} x $ and $ \tan^{-1} x $ assume values in $[-\frac{\pi}{2}, \frac{\pi}{2}]$ and $(-\frac{\pi}{2}, \frac{\pi}{2})$, respectively.)- JEE Advanced - 2025
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A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is:
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- Dimensional Analysis
- Let $$ \alpha = \frac{1}{\sin 60^\circ \sin 61^\circ} + \frac{1}{\sin 62^\circ \sin 63^\circ} + \cdots + \frac{1}{\sin 118^\circ \sin 119^\circ}. $$ Then the value of $$ \left( \frac{\csc 1^\circ}{\alpha} \right)^2 $$ is \rule{1cm}{0.15mm}.
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Concepts Used:
Ethers
A class of organic compounds that mostly contain an ether group in which the oxygen atom is bonded to two alkyl or aryl groups are referred to as Ethers. For the same, C-O-C is the functional group.
Chemical Properties of Ether:
Ethers are less polar as well as less reactive, and they do not react with active metals (Na, K), cold dilute acid, oxidizing and reducing agents or other chemicals.
The reason is that they do not have an active functional group.
- Because of the presence of a lone pair on the oxygen atom, ether has a basic nature and behaves like a Lewis base. Formation of oxonium ion occurs when ethers react with cold conc. acid. Ethers, such as BF3, AICI3, and RMgX, form a dative bond with Lewis acid.
- There is a significant difference between the boiling points of ethanol and dimethyl ether. Ethanol has very much higher boiling point of 78 degrees Celsius, whereas dimethyl ether has a negative 25 degrees boiling point. And this explains the molecules' state of matter.
- Ethanol is, of course, a liquid at room temperature and pressure because its boiling point is higher than room temperature. On the other hand, Dimethyl ether already has turned into a gas due to its much lower boiling point.