Final answer:
Among the listed compounds, only 1-butene (CH2=CHCH2CH3) demonstrates cis-trans isomerism because it has two different groups attached to each carbon of the double bond; the others do not meet the criteria for cis-trans isomerism. Option C is correct.
Step-by-step explanation:
Understanding Cis-Trans Isomerism
Cis-trans isomerism, also known as geometric isomerism, is a form of stereoisomerism where isomers have the same molecular formula but differ in the orientation of substituents around a double bond or a ring structure. For alkenes, cis-trans isomerism occurs when each carbon of the double bond has two different groups attached to it. To exhibit cis-trans isomerism, such a compound must not have identical groups attached to either carbon of the double bond.
Considering the compounds listed:
CHF=CHF does not show cis-trans isomerism because it has identical groups (F) on one carbon of the double bond.
F2C=CH3 does not show cis-trans isomerism as one carbon of the double bond does not have two different groups; it has two fluorine atoms.
CH2=CHCH2CH3 (1-butene) shows cis-trans isomerism because there are four different groups around the double bond – hydrogen and methyl on one carbon, and ethyl and hydrogen on the other.
Thus, the compound that can exist as cis-trans isomers is 1-butene (CH2=CHCH2CH3).