Q6 of 33 Page 225

Ethanol is heated with excess concentrated H2SO4 at 443K.

i) Name the reaction that occurs and explain it.


ii) Write the equation for the above reaction.


iii) What is the product formed? What happens when this gas is passed through bromine water?


iv) When ethanol vapour is passed through bromine water, why does no change occur?


i) When ethanol is heated with excess conc. H2SO4 at 443K, it undergoes intra molecular dehydration (i.e. removal of water within a molecule of ethanol) to give ethene.


The reaction is intra molecular dehydration reaction.


ii) The equation for the above reaction is:



iii) The product formed is ethane (alkene), an unsaturated hydrocarbon which contains a double bond.


When this is passed through bromine water, it decolourises the water. It means decolourisation occurs.


iv) When ethanol vapour is passed through bromine water, no changes occur because it is neither a saturated nor an unsaturated hydrocarbon.


Ethanol is a functional group, hence no changes occur.


More from this chapter

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4


Look at the diagram and answer the following questions:


i) What type of structure do diamond and graphite have?


ii) Why are diamonds used in cutting tools?


iii) Why is graphite used in electrical circuits?


iv) Name the force that accounts for the softness of graphite.


v) Name the precious diamond you know and give its weight in grams.


 5

CnH2n+2 is the general formula of a homologous series of hydrocarbons.

i) Is this series saturated or unsaturated?


ii) Name the series described above. Give the formula and name of the member with two carbon atoms.


iii) Draw the structural formula of the first member of this series.


iv) Define the homologous series and find the common difference between the successive members of this family.


v) Write the formula of n-butane and n-pentane.


 7

Complete the following table:

 8

Ethanoic acid is a member of Homologous series with general formula

CnH2n+1 COOH.


i) Name the series and give its functional group.


ii) Give the molecular formula and the common name of ethanoic acid.


iii) If this compound is mixed with ethanol in the presence of Conc.H2SO4, a sweet smelling compound is formed. Give the equation and name the compound.


iv) Ethanoic acid reacts with carbonates. Which gas is liberated during this reaction?


v) Write the balanced equation for the reaction of ethanoic acid with carbonate.


vi) Your grandmother has prepared mango pickle. What has she added to preserve it for a long time?