Question

Number of the possible geometrical isomers for 1,3 – pentadiene is:
A.8
B.4
C.3
D.2

Answer 1

Hint:1,3 – pentadiene appears as a clear colorless liquid with an acrid colour. A dangerous fire risk. Vapors are irritating to the eyes and respiratory system. Subject to polymerization if heated or contaminated. If the polymerization takes place inside a container, the container may violently rupture. Insoluble in water. Used to make intermediates and polymers.

Complete answer:
There are only two isomers possible for 1,3 – pentadine. The geometrical isomers are:
Cis
Trans

Hence, option (D) is the correct answer.

Additional information:
Molecular formula of 1,3 – pentadiene is $C_5{H}_8$ . Isomerism the existence of molecules that have the same numbers of the same kinds of atoms but differ in chemical and physical properties. Such structure also would be analogous to isomers. In a more suitable analogy, One’s hands can be seen as isomeric. The roots of the word isomer are Greek-iso plus meroes or equal parts. Two make crude analogy, two bracelets, each consisting of five red and five beds, could be arranged in many different isomeric forms, depending on the order of the colours.

Note:
Structural isomers are molecules which have the same molecular formula but have different connectivities. Alkanes can be very simple examples of this. Isomers are compounds that contain exactly the same number of atoms. They have exactly the same empirical formula, but differ from each other by the way in which the atoms are arranged. There can be several isomers for each empirical formula.