Esterification

Q.

What is a general formula for an ester?

Q.

What happens when Ethyl alcohol and Acetic acid react together in the presence of conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$? Write the chemical equation of the reaction.

Q.

Which compound is formed when acetic acid reacts with ammonium hydroxide? Also, write the equation.

Q.

The structural formula of an ester is :

$H-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-\stackrel{O}{\stackrel{||}{C}}-O-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-\underset{H}{\underset{|}{\stackrel{H}{\stackrel{|}{C}}}}-H$

Write the formula of the acid and the alcohol from which it is formed.

Q. An organic compound A is widely used as a preservative in Pickles and has molecular formula C2H4O2. This compound reacts with ethanol to form a sweet smelling compound B
(I) Identify the compound A
(2)Write the chemical equation for it's reaction with ethanol to form compound B
(3)How can you get back compound A from compound B
(4)Name the process and the chemical equation for the conversion of B to A

Q. $C{H}_{3}COOH\left(aq\right)+C{H}_{3}C{H}_{2}OH\left(aq\right)\to C{H}_{3}COO{C}_2{H}_5\left(aq\right)+H_{2}O\left(aq\right)$
This reaction is named as

1. Saponification
2. Esterification
3. Elimination
4. Substitution

Q. Question 51
Esters are sweet smelling substance and are used in making perfumes. Suggest some activity and the reaction involved in the preparation of an ester with a well-labelled diagram.

Q. How would you distinguish experimentally between ethanol and ethanoic acid?

Q. Distinguish between esterification and saponification reaction with help of the chemical equation for each

Q. Heating a mixture of ethanol and ethanoic acid in presence of conc. ${\text{H}}_2{\text{SO}}_4$ produces a fruity smelling compound. This reaction is called __________ reaction.

1. neutralisation
2. esterification
3. hydrogenation
4. substitution

Q. Question 52
A compounds C (molecular formula ${\text{C}}_2{\text{H}}_4{\text{O}}_2$) reacts with $\text{Na}$ metal to form a compound R and evolves a gas which burns with a pop sound. Compound C on treatment with an alcohol A in presence of acid forms a sweet smelling compound S (molecular compounds ${\text{C}}_3{\text{H}}_6{\text{O}}_2$). On addition of $\text{NaOH}$ to C, it also gives R and water. S on treatment with $\text{NaOH}$ solution gives back R and A. Identify C, R, A, S and write down the reactions involved.

Q.

(a) Esters are sweet-smelling substances and are used in making perfumes. Describe an activity for the preparation of an ester with the help of a well-labelled diagram. Write an equation for the chemical reaction involved in the formation of the ester. Also writer the names of all the substances involved in the process of esterification.
(b) State any two uses of esters.

Q.

Write the chemical equations for the preparation of Acetic acid from : Ethyl Alcohol (or Ethanol)

Q.

Give balanced chemical equation for the conversion of Ethanoic acid to Ethyl ethanoate.

Q.

A neutral organic compound X of molecular formula $C_2{H}_{6}O$ on oxidation with acidified potassium dichromate gives an acidic compound Y. Compound X reacts with Y on warming in the presence of conc. $H_{2}S{O}_4$ to give a sweet-smelling substance Z. What are X, Y and Z?

Q.

Define the following.

Denatured spirit

Q.

____ is used in the manufacture of rayon fibre.

1. antacid syrup

2. carbonic acid

3. tartaric acid

4. ethanoic acid

Q.

An organic compound 'A' is a constituent of antifreeze and has the molecular formula C₂H₆O. Upon reaction with alkaline KMnO₄, the compound 'A' is oxidised to another compound 'B' with formula C₂H₄O₂ . ldentify the compounds 'A' and 'B'. Write the chemical equation for the reaction which leads to the formation of 'B'.

Q.

A neutral organic compound is warmed with some ethanoic acid and a little of conc. $H_{2}S{O}_4$. Vapours having a sweet smell (fruity smell) are evolved. What type of functional group is present in this organic compound?

Q.

(a) What happens when ethanol reacts with ethanoic acid in the presence of a little of concentrated sulphuric acid? Write an equation of the reaction involved.
(b) What happens when ethanol is heated with concentrated sulphuric acid at ${170}^{\circ }C$? Write the equation of the reaction which takes place.

Q.

Consider the following organic compounds :

$HCHO,C_2{H}_{5}OH,C_2{H}_{6}C{H}_{3}COOH,C_2{H}_{5}Cl$

Choose two compounds which can react in the presence of conc. $H_{2}S{O}_4$ to form an ester. Give the name and formula of the ester formed.

Q.

Carboxylic acids react with alcohols to form esters

1. False

2. True

Q.

Which of the following will give a pleasant smell of ester when heated with ethyl alcohol and a small quantity of sulphuric acid?

1. CH₃COOH

2. CH₃COCH₃

3. CH₃OH

4. CH₃CHO

Q.

An organic compound $A$has the molecular formula$C_4{H}_8{O}_2$ on hydrolysis gives product $B$and $C$ having molecular formula $C_2{H}_4{O}_2$and $C_2{H}_{6}O$, respectively. $B$ is used as vinegar in cooking. Identify $A$, $B$, and$C$; and also write the chemical equation involved in the formation of $B$ and$C$.

Q.

Choose the best option regarding ester:

Statement 1: Ester is formed due to the reaction between ethanol and ethanoic acid.

Statement 2: Esters are sweet smelling substances.

Statement 3: Ester are formed due to the reaction between an acid and a carboxylic acid.

Statement 4: On treating with sodium hydroxide, ester is converted back to alcohol and sodium salt of carboxylic acid.

Statement 5: Preparation of soap involves treating sodium hydroxide with ester.

1. All statements are correct

2. Only statement 1, 2 and 3 are correct

3. Only statement 5 is incorrect

4. Only statement 3 is incorrect

Q.

Esters are most commonly formed by reaction of an acid and an alcohol.

1. True

2. False

Q. Which amonst the following will give a pleasant smell of ester when heated with ethanol and a small quantity of sulphuric acid?

1. ${\text{CH}}_3\text{COOH}$
2. ${\text{CH}}_3\text{OH}$
3. ${\text{CH}}_3\text{CO}{\text{CH}}_3$
4. ${\text{CH}}_3\text{CHO}$

Q.

Complete the following equations and write the names of the products formed.
(i) ${CH}_{3}COOH$ + NaOH (ii) $C_2{H}_{5}OH$ + $O_2$
(iii) ${CH}_{3}COOH$ + $C_2{H}_{5}OH$

Q. Complete the following esterification reaction $C{H}_{3}COOH+C{H}_{3}C{H}_{2}OH\stackrel{H_{2}S{O}_4}{\to }$ + $H_{2}O$

1. $C{H}_{3}CO{C}_2{H}_5$
2. $C{H}_{3}COO{C}_2{H}_5$
3. $C{H}_{3}C{H}_{2}OC{H}_3$

Q. Ethanoic acid and ethanol can be distinguished by litmus test as well as by sodium bicarbonate test.

1. True
2. False