Dehydration Reaction

Q. Question 39
Ethene is formed when ethanol at 443k is heated with an excess of concentrated sulphuric acid. What is the role of sulphuric acid in this reaction? Write the balanced chemical equation for this reaction.

Q.

When ethanol is heated with concentrated sulphuric acid at ${170}^{\circ }C,$ it gets converted into ethene. In this reaction, concentrated sulphuric acid acts as :
(a) oxidising agent (b) catalyst (c) dehydrating agent (d) reducing agent

Q. When ethanol reacts with sulphuric acid it undergoes dehydration reaction to give :

1. Ethene
2. Methane
3. Propane
4. Ethyne

Q.

Name the hydrocarbon formed when ethanol is heated with conc. $H_{2}S{O}_{4}at{170}^{\circ }C$ ? What is this reaction known as?

Q.

An organic compound A having the molecular formula $C_3{H}_{8}O$ is a liquid at room temperature. The organic liquid A reacts with sodium metal to evolve a gas which burns causing a little explosion. When the organic liquid A is heated with concentrated sulphuric acid at ${170}^{o}C$, it forms a compound B which decolourises bromine water. The compound B adds on one molecule of hydrogen in the present of Ni as catalyst to form compound C which gives substitution reactions with chlorine.

(a) What is compound A ?

(b) What is compound B ?

(c) What type of reaction occurs when A is converted into B ?

(d) What is compound C ?

(e) What type of reaction takes place when B is converted into C ?

Q.

Will micelles be formed in other solvents like ethanol?

Q. Compound A is bubbled through bromine dissolved in carbon tetrachloride and the product is $C{H}_{2}Br-C{H}_{2}Br$
$A\stackrel{B{r}_2/CC{l}_4}{\to }C{H}_{2}Br-C{H}_{2}Br$
i) Draw the structural formula of A
ii) What type of reaction has A undergone?
iii) What is your observation?
iv) Name (not formula) the compound formed when steam reacts with A in the presence of phosphoric acid.
v) What is the procedure for converting the product of (iv) back to A?

[5 MARKS]

Q.

How would you convert :
(a) ethanol into ethene ?
(b) propanol into propanoic acid ?
Name the process in each case and write the equations of the reactions involved.

Q.

What happens when ethanol vapours are passed through the test tube containing alumina?

1. Ethene is formed.

2. Ethane is formed.

3. Ethane is formed.

4. Methanol is formed.

Q.

Convert ethanol into ethene using
(a) solid dehydrating agent
(b) hot conc. $H_{2}S{O}_4$ ?
Give only balanced equations.

Q.

The organic compound mixed with Ethanol to make it spurious is

1. Methanol

2. Methanoic acid

3. Methanal

4. Ethanoic acid

Q. How is ethanoic acid prepared from ethanol? Give the chemical equation.​

Q.

Ethanol is heated gently in a water bath as shown in the set-up. When potassium permanganate is added in excess, the pink color of potassium permanganate disappears due to the formation of which compound?

1. Acetic acid

2. Propanoic acid

3. Methanoic acid

4. Formic acid

Q.

Give the balanced equation for the following reaction:

Dehydration of formic acid by conc. sulphuric acid.

Q.

Give the inter-relationship of methane, methyl alcohol, formaldehyde and formic acid with conditions.

Q.

Complete the following equations :
(a) $C{H}_{3}C{H}_{2}OH\underset{{170}^{\circ }C}{\overset{Conc.H_{2}S{O}_4}{\to }}$
(b) $C{H}_{3}COOH+C_2{H}_{5}OH\stackrel{Conc.H_{2}S{O}_4}{\to }$

Q. The gas formed when ethanol is treated with hot concentrated sulphuric acid is _____.

1. ethene
2. ethane
3. methene
4. methane

Q.

How is Ethanol converted to Ethene using a solid dehydrating agent?

Q. A compound X is formed by the reaction of carboxylic acid having the molecular formula C2 H4 O2 and alcohol Y in the presence of concentrated H2 s o4 the same carboxylic acid is obtained by oxidation of alcohol Y name the compound X and Y give the chemical equation for the reaction

Q.

Under what conditions does ethanol react with sulphuric acid to produce the colourless gas ethene? Write an equation for this reaction.

Q. The addition of sulphuric acid to ethanol results in the formation of ethene and water. This shows that sulphuric acid is a _______.

1. Catalyst
2. Oxidizing agent
3. Reducing agent
4. Dehydrating agent

Q. Ethene is formed when ethanol at 443 K is heated with an excess of concentrated sulphuric acid. The role of sulphuric acid in this reaction is :

1. it acts as an acid
2. it acts as a dehydrating agent
3. it acts as an oxidising agent
4. none of these

Q.

A dehydration reaction is a reaction in which there is

1. Addition of Water

2. Loss of Water

3. Addition of Hydrogen

4. Loss of Hydrogen

Q. What is the nature of the carbon-carbon bond(s) in the compound formed when concentrated $H_{2}S{O}_4$ dehydrates ethanol?

1. 1
2. 2
3. 3
4. none

Q.

How Are Alcohols Acylated?

Q. A dehydration reaction is a reaction in which there is _______ .

1. an addition of water
2. a loss of water
3. an addition of hydrogen
4. a loss of hydrogen

Q.

Name the following:

(i) Process by which ethane is obtained from ethene.

(ii) A hydrocarbon which contributes towards the greenhouse effect.

(iii) Distinctive reaction that take place when ethanol is treated with acetic acid.

Q. ___ is the gas formed when Ethanol is treated with hot concentrated sulphuric acid

Q. What is the number of carbon- carbon bonds in the compound formed when concentrated $H_{2}S{O}_4$ dehydrates ethanol?

1. 2
2. 3
3. 0
4. 1

Q. The gas formed when ethanol is treated with hot concentrated sulphuric acid is _____.

1. Ethane
2. Methene
3. Methane
4. Ethene