You are given three test tubes that contain colourless liquid. One test tube contains benzene, another contains ethanol, and the third contains 2,4-hexadiene. Design a procedure that will tell you the contents of each test tube. Describe your expected observations.

So benzene is an aromatic, ethanol is an alcohol, and hexadiene is an alkene. I'm not sure where to go from here.. please help :)

Try using this information. Ethanol dissolves in water. Does benzene? Does 2,4-hexadiene?

The diene adds Br2 to it easily. What can you do with that?

hmmmm..

well what methods should i be using?
should i add water to each of them, and i will know that the only homogenous mixture is ethanol. Then I could add Br2 to the remaining ones, and the 2,4-hexadiene will be uniform, leaving me with the benzene?
am i on the right track?

To determine the contents of each test tube, you can perform a series of tests based on the chemical properties of benzene, ethanol, and 2,4-hexadiene. Here's a step-by-step procedure you can follow:

1. Ignition test: Take a small amount of liquid from each test tube and apply it to a flame. Observe the flame color and the behavior of the liquid as it burns. Note down your observations.

- Benzene: When benzene burns, it produces a sooty flame with a yellowish color.
- Ethanol: Ethanol burns with a blue flame that is almost invisible during daylight. It might also produce a popping sound.
- 2,4-hexadiene: Hexadiene is highly flammable and should also burn with a yellowish flame, similar to benzene.

2. Bromine water test: Fill three separate test tubes with equal amounts of the colorless liquid from each of the original test tubes. Add a few drops of bromine water to each test tube and observe any color change.

- Benzene: Benzene does not react with bromine water, so there will be no visible color change.
- Ethanol: Ethanol reacts with bromine water, turning it from orange to colorless.
- 2,4-hexadiene: Hexadiene is an alkene and will decolorize bromine water, turning it from orange to colorless.

By combining the observations from the ignition test and the bromine water test, you can conclude the contents of each test tube:

- The test tube with the liquid that produces a yellow flame during the ignition test contains either benzene or 2,4-hexadiene.
- The test tube that decolorizes bromine water contains 2,4-hexadiene.
- The remaining test tube should contain benzene, and the last test tube will contain ethanol.

Please note that this is a basic procedure to distinguish between these three compounds, and additional tests may be necessary for a more definitive identification.