Identify structure(s) for all constitutional isomers with the molecular formula C4H8 that have one double bond. Select all that apply.

a) But-1-ene

b) E-But-2-ene

c) Z-But-2-ene

d) 2-Methylpropene

Explanation:

In this case, if we want to draw the isomers, we have to check the formula in this formula we can start with a linear structure with 4 carbons. We also know that we have a double bond, so we can put this double bond between carbons 1 and 2 and we will obtain But-1-ene.

For the next isomer, we can move the double bond to carbons 2 and 3. When we do this can have two structures. When the methyl groups are placed on the same side we will obtain Z-But-2-ene. When the methyls groups are placed on opposite sides we will obtain E-But-2-ene.

Finally, we can use a linear structure of three carbons with a methyl group in the middle with a double bond, and we will obtain 2-Methylpropene.

See figure 1 to further explanations.

I hope it helps!

the answer is definitely c.