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

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

  1. saturated fatty acids

  2. unsaturated fatty acids

  3. simple lipids

  4. phospholipids
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

The correct structural formula of butanoic acid is

  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. $H-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\underset{H}{\underset{|}{\overset{H}{\overset{|}{C}}}}-\overset{O}{\overset{||}{C}}-OH$
Reveal answer Fill a bubble to check yourself
D Correct answer
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 $D$
Multiple choice chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

The functional group present in carboxylic acids is ?

  1. -COOH

  2. -CO-

  3. -OH

  4. -CHO
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  1. intermolecular hydrogen bonding in ethers

  2. dipolar character of ethers

  3. alcohols having resonance structures

  4. intermolecular hydrogen bonding in alcohols
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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:

  1. $C _2H _5OC _2H _5$
  2. $CH _3{\underset{OCH _3}{\underset{|}{C}}}HCH _3$
  3. $CH _3CH _2CH _2OCH _3$
  4. $CH _3CH _2CH _2CH _2OH$
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

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

  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. $(CH _3) _3COC _2H _5 \xrightarrow{HI} (CH _3) _3CI + C _2H _5OH$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

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

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

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