Question

Give $IUPAC$ name of $C{H_2} = CH - CH = C{H_2}$.

Answer 1

Hint: To calculate $pH$ first of all we have to find concentration of ${H^ + }$ ion also $pH = - \log \left[ {{H^ + }} \right]$ and to calculate $pOH$ we have to calculate concentration of $O{H^ - }$ ion in the resulting solution . We should remember the formula $pH + pOH = 14$.

Complete step by step answer:
In this question we have to find the $IUPAC$ name of $C{H_2} = CH - CH = C{H_2}$. In this compound there are four carbon atoms in the main chain and there are two double bonds in this compound. Since there are four carbon atoms in the main chain, prefix but will be used. According to the rules of nomenclature, if there are more than one double or triple bonds then an extra a is added to the prefix. Therefore in this compound prefix will be buta. Suffix ene is used to represent double bonds. There are two double bonds, to represent these bonds word di will be used. Therefore the suffix used in this compound will be diene. Now we have to mention the position of double bonds. In this compound there will be no effect whether we start numbering from left or right, bonds will get the same position from both the ways. In this compound bonds are present at the first and third carbon atom. So, the name of the compound will be $1,3 - $butadiene.


Note:
 In this case bonds are getting the same position from both sides but if we were given the compound, whose bonds would be at different positions from different sides, we would start numbering from the side from which first bond (from that side) will get the lowest number.