Chemistry · Science General

Alcohols, Ethers and Carboxylic Acids

391 Questions

Alcohols, ethers, and carboxylic acids questions explore organic chemistry reactions, chemical formulas, and compound identifications. The topics cover practical applications like antifreeze production and specific chemical conversions. This material helps candidates preparing for science oriented competitive exams.

Organic reactionsChemical compounds identificationAlcohol conversionCarboxylic acid propertiesIndustrial chemical applications

Alcohols, Ethers and Carboxylic Acids Questions

Multiple choice chemistry alcohols, esters and carboxylic acids reduction of carboxylic acids chemical properties chemical properties of carboxylic acids

Methyl alcohol when reacted with carbon monoxide using cobalt or rhodium as catalyst , compound $'A'$ is formed. $'A'$ on heating with HI in the presence of red phosphorus as catalyst $'B'$ is formed. $'B'$ is:

  1. $CH _3COOH$
  2. $CH _3CHO$
  3. $CH _3CH _2I$
  4. $CH _3CH _3$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$CH _3OH+CO\xrightarrow [ (High\quad Pressure) ]{ CO/Rh } \underbrace{ CH _3COOH} _{Compound A}$

Alcohol with carbon monoxide in presence of  $CO/Rh$ gives carboxylic Acid.
$CH _3COOH\quad \underrightarrow{Red P+HI}\quad CH _3-CH _3$
$Red P+HI$  is areducing agent and reduces carboxylic acid into hydrocarbons.

Multiple choice chemistry alcohols, esters and carboxylic acids reduction of carboxylic acids chemical properties chemical properties of carboxylic acids

Alcohols can be obtained from carboxylic acids by reduction using one of the following reagents:

  1. $LiAIH _{4}$
  2. $N/alcohol$
  3. $Zn/HCl$
  4. $H _{2}/Ni$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$RCOOH  +  LiAlH _4 \rightarrow RCHO  \rightarrow RCH _2OH $

Carboxylic acids along with lithium aluminium hydride, initially gives aldehyde and then reduced to primary alcohols.

Multiple choice reactions of haloarenes haloalkanes and haloarenes chemistry

Which one of the following would not be a suitable solvent for Grignard reagent?

  1. $CH _{3}CH _{2}OCH _{2}CH _{3}$, diethylether

  2. tetrahydrofuran (THF)
  3. $CH _{3}CH _{2}OH$, ethanol

  4. They would all be suitable solvent.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethanol has acidic hydrogen, when we use ethanol as solvent it will react with grignard reagent, so it cannot be used as solvent in grignard synthesis. 

Multiple choice reactions of haloarenes haloalkanes and haloarenes chemistry

A student was carrying out a Grignard reaction between $PhMgBr$ and ethyl benzoate. She ran out of anhydrous ether just after the Grignard reagent was made. Which of the following solvents can still used to dissolve the ethyl benzoate for its reaction with already formed $PhMgBr$

  1. acetone

  2. ethyl acetate

  3. absolute alcohol

  4. benzene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Solution:- (D) benzene

Grignard reagent contains $R$-group which does nucleophilic addition on acetone and accepts Proton from alcohol.
Thus non polar benzene should be taken to carry out above reaction. 

Multiple choice chemistry organic compounds containing nitrogen chemical reactions of diazonium salts chemical properties of diazonium salts diazonium salts

When diazonium salt solution is treated with water at a temperature of 283 K it forms:

  1. ester

  2. alcohol

  3. amines

  4. phenol
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When an aqueous solution of an aromatic diazonium salt is warmed (often at temperatures around 283-300 K), it undergoes hydrolysis to form phenol and nitrogen gas.

Multiple choice chemistry organic compounds containing nitrogen chemical reactions of diazonium salts chemical properties of diazonium salts diazonium salts

Which of the following is correct method to convert p-toluidine to p-toluic acid?

  1. $ Diazotisation, \, CuCN, \, H _2/Pd$
  2. $CHCl _3/NaOH,\, KCN, \, Sn/HCl$
  3. $ Diazotisation, \, CuCN/KCN, H _2O/H^+$
  4. $ Diazotisation, \, NaCN, \, NaOH$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To convert p-toluidine to p-toluic acid, one must diazotize the amine, replace the diazonium group with a cyano group using CuCN, and then hydrolyze the nitrile to a carboxylic acid.

Multiple choice chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

Which of the following is not correctly matched with its uses ?

  1. Methanol : As a solvent for paints , varnishes etc.

  2. Ethanol : For denaturing spirit, in manufacture of formaldehyde.

  3. Ethers : To provide inert medium for chemical reactions , as anaesthetic.

  4. All are correctly matched.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Uses of Methanol are:
1. As a fuel. Methanol burns in air to give carbon dioxide and water.
$2CH _3OH + 3O _2 \rightarrow 2CO _2 + 4H _2O$
2. As a useful fuel for stunt and racing cars as it is less inflammable and can be mixed with water.
3. It is also used as a solvent.
4. Manufacturing other chemicals such as formaldehyde.
5. Being a polar liquid at room temperature, it is used as antifreeze and a denaturant for ethanol.
Uses of Ethanol
1. The alcohol that we drink is simply ethanol.
2. It is also used as a fuel. It burns in air to give carbon dioxide and water and can be used in combination with gasoline (petrol).
$CH _3CH _2OH + 3O _2 \rightarrow 2CO _2 + 3H _2O$

3. A mixture of petrol and ethanol is defined as gasohol with 10-20% ethanol.
4. Ethanol is one of the main ingredients in cosmetics and beauty products.
5. It is used as a food additive. Ethanol helps in evenly distributing food color. It also helps in enhancing the flavor of food extracts.
6. Ethanol is an effective agent that can kill microorganisms like bacteria, viruses, and fungi. Many hand sanitizers use this chemical compound.

Uses of Ether:
Ethers are liquid at room temperature and are typically colorless, with a sweet smell. The most common type of ether is diethyl ether, which is extremely flammable and was one of the first anesthetics used in surgery. Due to its anesthetic effects, ether is also used as an illicit drug to induce sedation and euphoria.

Multiple choice chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

Alcoholic beverages contain:

  1. Glycerol

  2. Ethyl alcohol

  3. Methyl alcohol

  4. Isopropyl alcohol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alcoholic beverages contain ethyl alcohol (ethanol). Alcohol by volume(ABV) is a standard measure of how much alcohol ethyl alcohol is contained in a given volume of an alcoholic beverage.

Multiple choice chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

Which of the following is an application of ethyl alcohol?

  1. as an antiseptic

  2. as an antipyretic

  3. as an antiallergic

  4. as a coagulating agent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethanol is used in medical wipes and in most common antibacterial hand sanitizer gels at a concentration of about 62% v/v as an antiseptic. Ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria and fungi, and many viruses, but is ineffective against bacterial spores.

Multiple choice chemistry chemical reactions of organic compounds uses of alcohols commercially important alcohols - ethanol some commercially important alcohols commercially important alcohols - methanol methanol

Which of the following alcohol is used for making acetaldehyde?

  1. Ethanol

  2. Methanol

  3. Propanol

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethanol is used to prepare acetaldehyde.

$CH _{3}CH _{2}OH + [O] \xrightarrow{KMnO _{4}} CH _{3}CHO + H _{2}O$
So. ethanol on oxidation with potassium permanganate forms acetaldehyde as a product.

Multiple choice organic compounds with functional group containing oxygen (part-1) uses of alcohols commercially important alcohols - ethanol some commercially important alcohols

Rectified spirit can be converted into Absolute alcohol by distilling with?

  1. $NaCO _{3}$
  2. $Mg(OC _{2}H _{5}) _{2}$
  3. $CaO$

  4. Both 2 & 3

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the laboratory, Absolute alcohol is prepared by keeping the rectified spirit in contact with calculated amount of quick lime $(CaO)$ for a few hours and then refluxing and distilling it.

Multiple choice organic compounds with functional group containing oxygen (part-1) uses of alcohols commercially important alcohols - ethanol some commercially important alcohols

Power alcohol is:

  1. absolute alcohol : petrol (20:80)

  2. absolute alcohol : petrol (80:20)

  3. rectified spirit : benzene (20:80)

  4. rectified spirit : benzene (80:20)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Power alcohol is 20 : 80 mixture of absolute alcohol and petrol.
It is used to generate power.
Power alcohol is an additive to motor fuels to act as fuel for internal combustion engine.

Multiple choice organic compounds with functional group containing oxygen (part-1) uses of alcohols commercially important alcohols - ethanol some commercially important alcohols

Absolute alcohols (100% ethanol) are prepared from rectified spirit (95% ethanol) by mixing a suitable amount of ............... and subjected to fractional distillation (azeotropic distillation).

  1. Toluene

  2. o-Xylene

  3. Methanol

  4. Benzene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Absolute alcohols (100% ethanol) are prepared from rectified spirit (95% ethanol) by mixing a suitable amount of benzene and subjected to fractional distillation (azeotropic distillation).

Multiple choice organic compounds with functional group containing oxygen (part-1) uses of alcohols commercially important alcohols - ethanol some commercially important alcohols

Absolute alcohol can be prepared from rectified spirit by _____ distillation.

  1. vacuum

  2. fractional

  3. azeotropic

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Absolute alcohol can be prepared from rectified spirit by azeotropic distillation. Absolute alcohol is 100% pure alcohol. Rectified spirit contains 95.87% ethanol and 4.13% water. It is a constant boiling mixture having boiling point 78.13 $^oC$.