Question
Question: The product of ozonolysis of an alkene is ethanal and methanal, then that alkene is A.\[{\text{C}}...
The product of ozonolysis of an alkene is ethanal and methanal, then that alkene is
A.CH3−C≡C−CH3
B.CH3−CH=CH−CH3
C.CH3−CH=CH2
D.CH3−C≡CH
Solution
In the above question we have been given the product of ozonolysis and we have to search for a reactant. Oxygen adds up in the unsaturation of alkenes and the total number of carbon remains same in reactant and product.
Complete step by step answer:
Ozonolysis is an organic reaction in which the ozone molecule is used for breaking the unsaturated bond and converting it into a carbonyl group.
We have been given two products that are formed by ozonolysis of an alkene. So the reactant species is an alkene that means it has a double bond in it. If we look at the above options, option A and D has triple bonds or are alkynes. Hence we can eliminate option A and D from here.
The ‘al’ function group refers to the aldehyde functional group.
The chemical formula for methanal is HCHO. The formula for ethanal is CH3CHO. In ozonolysis oxygen gets added up in a double bond. Hence the number of carbon should remain constant in the product and reactant. In the two products forms have total 3 carbons, one carbon in HCHO and two carbon in CH3CHO. According to this the reactant should have total tree carbon which is in option CH3−CH=CH2. The reaction occurs as follow:
CH3−CH=CH2ozonolysisHCHO+CH3CHO
Hence the correct option is C.
Note:
Ozone has a molecular formula as O3. It is an allotrope of oxygen and is less stable than oxygen. It has formed a very thin layer on the earth’s atmosphere and most of its concentration lies in the stratosphere. It is colourless to pale blue in colour and is soluble in carbon tetrachloride.