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Questions Related to chemistry

Acetic acid is present in vinegar. Curd contains ______ .

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. lactic acid

  2. tartaric acid

  3. picric acid

  4. None of the above

Show answer
Correct Option: A
Explanation:

Lactic acid is present in curd. The increased acidity causes the milk proteins to tangle into curds. 

$C _nH _{2n-1}COOH$ is the general formula for:

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. saturated fatty acids

  2. unsaturated fatty acids

  3. simple lipids

  4. phospholipids

Show answer
Correct Option: B
Explanation:

$C _nH _{2n-1}COOH$ is a general formula for unsaturated fatty acids.

For example: $CH _2=CH-COOH$
Propenoic acid $C _2H _3COOH$
$C _nH _{2n+1}COOH$ is general formula for saturated fatty acids.
For example: $CH _3COOH$ is Ethanoic acid.

The correct structural formula of butanoic acid is

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. $H-\overset{H}{\overset{|}{\underset{H}{\underset{|}{C}}}}-\overset{H}{\overset{|}{C}}=\overset{H}{\overset{|}{C}}-\overset{O}{\overset{||}{C}}-OH$

  2. $H-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{O}{\overset{||}{C}}}}-OH$

  3. $H-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-OH$

  4. $H-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\overset{O}{\overset{||}{C}}-OH$

Show answer
Correct Option: D
Explanation:
Butanoic acid is a carboxylic acid with the structural formula CH3CH2CH2-COOH. where $-COOH$ is the functional group.

$H-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\overset{O}{\overset{||}{C}}-OH$

So, the correct representation of butanoic acid is $D$

The functional group present in carboxylic acids is ?

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. -COOH

  2. -CO-

  3. -OH

  4. -CHO

Show answer
Correct Option: A
Explanation:

Carboxylic acids are represented by -COOH- functional group. It ionizes to give carboxylate ions and hydrogen ions. This group present in a compound makes it an acid and if present with other groups in the compound it is always present at position no.1 and carbon is included in the carbon chain atoms.

The general formula of carboxylic acids is:

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. $C _{n}H _{n}COOH$

  2. $C _{n}H _{2n}COOH$

  3. $C _{n}H _{2n-2}COOH$

  4. $C _{n}H _{2n+1}COOH$

Show answer
Correct Option: D
Explanation:

General formula of acids is: $C _{n}H _{2n+1}COOH$.

For example: for n=1 we get $CH _3-COOH$ which is acetic acid.

IUPAC name of $CH _3COOH$ is:

chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

  1. acetic acid

  2. formic acid

  3. methanoic acid

  4. ethanoic acid

Show answer
Correct Option: D
Explanation:

It has 2 carbon atoms, and functional group is carboxylic group,suffix is "oic acid"
 thus IUPAC name is Ethanoic acid

An ether is more volatile than alcohol having the same molecular formula. This is due to:

chemistry hydroxy compounds and ethers chemical properties of ethers ethers alcohols, phenols and ethers

  1. intermolecular hydrogen bonding in ethers

  2. dipolar character of ethers

  3. alcohols having resonance structures

  4. intermolecular hydrogen bonding in alcohols

Show answer
Correct Option: D
Explanation:

An ether which is almost nonpolar is more volatile than alcohol having same molecular formula .this is due to intermolecular hydrogen bonding in alcohols .so alcohols have high bonding point.

An organic compound with molecular formula $C _4H _{10}O$ does not react with sodium . With excess of HI it gives only one type of alkyl halide. The compound is:

chemistry hydroxy compounds and ethers chemical properties of ethers ethers alcohols, phenols and ethers

  1. $C _2H _5OC _2H _5$

  2. $CH _3{\underset{OCH _3}{\underset{|}{C}}}HCH _3$

  3. $CH _3CH _2CH _2OCH _3$

  4. $CH _3CH _2CH _2CH _2OH$

Show answer
Correct Option: A
Explanation:

$C _4H _{10}O$ can have two structures :


$CH _3CH _2CH _2CH _2OH$   and  $C _2H _5OC _2H _5$.

Since it does not react with Na metal, it can not be an alcohol.

$C _2H _5OC _2H _5 + \underset{excess}HI\rightarrow 2C _2H _5I + H _2O$

Which of the following products are not correctly matched in the given reactions?

chemistry hydroxy compounds and ethers chemical properties of ethers ethers alcohols, phenols and ethers

  1. $C _2H _5OCH _3 + HBr \xrightarrow{373K} C _2H _5OH + CH _3Br$

  2. $C _2H _5OC _2H _5 + 2HI \rightarrow C _2H5I + C _2H _5OH$

  3. $C _2H _5OC _2H _5 + \overset{Excess}{HCl} \xrightarrow{Cold} [(C _2H _5) _2O^+H]Cl^-$

  4. $(CH _3) _3COC _2H _5 \xrightarrow{HI} (CH _3) _3CI + C _2H _5OH$

Show answer
Correct Option: B
Explanation:

$C _2H _5-O-C _2H _5 +\underset{(excess)} 2HI \rightarrow 2C _2H _5I + H _2O$

Anisole on reaction with chloromethane in presence of anhydrous $AlCl 3$ gives __________.

chemistry hydroxy compounds and ethers chemical properties of ethers ethers alcohols, phenols and ethers

  1. o-methyl anisole and p-methoxy anisole

  2. p-methyl anisole and p-methoxy anisole

  3. o-methyl anisole and p-methyl anisole

  4. o-methoxy acetphenone and p-methoxy acetophenone .

Show answer
Correct Option: C
Explanation:
Anisole i.e. Phenyl methyl ether $CH _3OC _6H _5$ reaction with Chloromethane in the presence of anhy $AlCl _3$ electrophilic substitution reaction at ortho and para position w.r.t. methoxy group on benzene ring. It is called Friedel-craft alkylation reaction and represented as:
$C _6H _5OCH _3+ CH _3Cl \overset {AlCl _3}{\rightarrow} o-CH _3C _6H _5OCH _3+p-CH _3C _6H _5OCH _3$
Hence Anisole on reaction with chloromethane in presence of anhydrous AlCl3 gives o-methyl anisole and p-methyl anisole