Alkanes and alkenes are both hydrocarbons. Alkanes, however, contain only single bonds between the carbons while alkenes contain at least one double bond between carbons. Tests can be conducted to differentiate these two groups of molecules based on whether or not the double bonds can be broken by a halogen. If one takes two test tubes with bromine water and adds an alkene to tube A and an alkane to tube B and then shakes... Alkanes and alkenes are both hydrocarbons. Alkanes, however, contain only single bonds between the carbons while alkenes contain at least one double bond between carbons. Tests can be conducted to differentiate these two groups of molecules based on whether or not the double bonds can be broken by a halogen. If one takes two test tubes with bromine water and adds an alkene to tube A and an alkane to tube B and then shakes the two tubes, a color change will occur in tube A (the color of the solution will change from brown to colorless) while no color change will occ...