Q: Which one is the most acidic compound?

Hint: The acidity of a species depends on its power to remove hydrogen ions.Explanation: Step 1: Acidic character dependence If an electron-withdrawing group is attached to a benzene ring then the group will attracts the ring electrons which facilitate the release of hydrogen ions and the species become more acidic. If an electron-donating group is attached to a benzene ring then the group will supply electrons to the ring which does not release hydrogen ions easily and the species become least acidic. Step 2: Acidity comparison This compound has three electron-withdrawing groups NO_2 . So it will withdraw the electrons from the O-H bond and the bond breaks easily. So, it is most acidic. This compound has one electron-withdrawing group NO_2 . So, it will also pose higher acidity. This compound has an electron-donating group so, it is the least acidic.This compound is moderately acidic due to the presence of the hydroxyl group.The order of acidity of the compounds is A > D > C > B Correct Option : A

Question 1

The heating of phenyl-methyl ether with  HI  produces :

Accepted Answer

The heating of phenyl-methyl ether with  HI  produces phenol.

Question 2

Which one is the most acidic compound?

Accepted Answer

Hint: The acidity of a species depends on its power to&#10;remove hydrogen ions.Explanation:&#10;&#10;Step 1: Acidic character dependence&#10;&#10;If an electron-withdrawing group is attached to a&#10;benzene ring then the group will attracts the ring electrons which facilitate&#10;the release of hydrogen ions and the species become more acidic.&#10;&#10;If an electron-donating group is attached to a benzene&#10;ring then the group will supply electrons to the ring which does not release hydrogen&#10;ions easily and the species become least acidic.&#10;&#10;Step 2: Acidity comparison&#10;&#10;This compound has three electron-withdrawing groups&#10; NO_2 . So it will withdraw the electrons from the  O-H  bond and the bond breaks easily. So, it is most acidic.&#10;&#10;This compound has one electron-withdrawing group&#10; NO_2 . So, it will also pose higher acidity.&#10;&#10;This compound has an electron-donating group so, it&#10;is the least acidic.This compound is moderately acidic due to the presence of the hydroxyl group.The order of acidity of the compounds is  A > D > C > B  &#10;&#10;Correct Option :  A

Question 3

In the reaction the electrophile involved is:

Accepted Answer

In the reaction the electrophile involved is dichlorocarbene  (:CCl_{2}) .In Reimer-Tiemann reaction, phenol in presence of NaOH reacts with chloroform to give salicyladehyde. Option C is correct.

Question 4

The compound  A  on treatment with  Na  gives  B , and with  PCl_{5}  gives  C. B  and  C  react together to give diethyl ether.  A, B  and  C  are in the order.

Accepted Answer

The compound A is ethanol  \displaystyle C_{2}H_{5}OH .  The compound A on treatment with  Na  gives sodium ethoxide  \displaystyle  (C_{2}H_{5}ONa)  which is compound B. \displaystyle C_{2}H_{5}OH \xrightarrow [-H_2]{Na} C_{2}H_{5}ONa The compound A on treatment with  PCl_5  gives ethyl chloride  \displaystyle ( C_{2}H_{5}-Cl)  which is compound C. \displaystyle C_{2}H_{5}OH  \xrightarrow {PCl_5} C_{2}H_{5}-Cl+HCl+POCl_3 B and C react together to give diethyl ether. \displaystyle C_{2}H_{5}ONa+C_{2}H_{5}Cl \rightarrow C_{2}H_{5}OC_{2}H_{5}+NaCl A,B and C are in the order  \displaystyle C_{2}H_{5}OH, C_{2}H_{5}ONa, C_{2}H_{5}Cl .Option C is correct.

Alcohols, Phenols And Ethers