Question

IUPAC name of acraldehyde is ?
(A) $prop - 2 - en - 1 - al$
(B) $propionaldehyde$
(C) $But - 2 - en - 1 - al$
(D) $propanal$

Answer 1

For giving IUPAC name to a compound always take care of the rules in IUPAC nomenclature
The suffix of aldehyde will be -$al$, and while numbering ,the functional group with more priority should get the least number.

Complete step by step answer:
Firstly to solve this question we need to know about the IUPAC(international union for pure and applied chemistry) ,to give compound a particular name certain rules should be followed for this IUPAC nomenclature is used, it enables the compound to have a unique name.
This has certain rules to be followed,
Find and name the longest carbon chain,, identify the name group attached to the chain, number the chain consecutively starting at the end nearest a substituent group , designate the location of each substituent group by appropriate number and name, naming in alphabetical order, determine the functional group this will determine the suffix.
In this question we have to determine the IUPAC name of acraldehyde , acraldehyde is also known as acrolein it is a simple unsaturated aldehyde
The structure of acraldehyde will be $C{H_2} = CH - CHO$
Here the functional group attached to the main chain is aldehyde so we will number the chain starting from the attached functional group $C{H_2} = CH - CHO$
So, there is total 3 carbon in the main chain so the word root will be prop
As there is double bond (alkene) at 2nd position the suffix will be ( $ene$)
And the functional group aldehyde will make the secondary suffix ( $al$ )
So the IUPAC name of the compound will be
$prop - 2 - en - 1 - al$
Hence the correct answer will be option (A).

Note:
Aldehyde is a functional group with structure $- CHO$, consist a carbonyl center with the carbon atom also bonded to hydrogen and a R-group its suffix will be ($al$)
Alcohol –$ol$, Ketone - $one$
Aldehydes have higher priority than ketone followed by alcohol.