Why is gasoline colorful

When the light is reflected off the oil in the gasoline, it will show different colors depending on the thickness of the oil at that part. The rainbow of colors comes from the thickness of the oil, with thicker parts giving off the blues and purples and the thinner parts giving off the reds pinks and yellows. First of all, not everyone enjoys the smell of gasoline. There are a large number of people who feel nothing positive or negative towards the smell, or even dislike it. Due to its high octane rating, it is less likely for combustion to take place at the wrong time.

The original color of gasoline is transparent. Basically, once gasoline is extracted, all you will see is a clear, transparent liquid. This then brings up the question, why do we have different colored gasoline types. The reason for this is simple. Many petroleum manufacturers usually add dyes colors to this clear liquid.

This helps them differentiate the different grades of gasoline. With this, mishaps in some applications are easily prevented. Another reason is that it makes it easier for people to test for water contamination. Basically, testing for water would be challenging if all types looked clear. The reasons for this is because both gasoline and water would look the same. Therefore adding dyes makes the water stand out when in a separation cylinder.

Different dye colors are used in each one of the gasoline types. This makes it easier to differentiate them. Here are the colors of each gasoline type. The existence different-colored types, begs the question, does color really matter? To answer this question, we need to look at this from two different perspectives. One of these perspectives is when you are pumping fresh gasoline from the gas station. Here the color of gasoline has no effect at all as long as it is fresh.

The other scenario is when you are storing gasoline. Here you need to pay close attention to the gasoline as time goes by. When you store gasoline, regardless of the dye used, it will have a transparent-like nature. Now, this is the best kind of gasoline to use. As time goes by, the color of the gasoline will change.

This is usually caused by oxidation. Oxidation is the process by which a substance gasoline in this case combines with oxygen. Color is not the only thing that changes when you store gasoline for a certain period of time. As gasoline gets older, you will notice that the scent too changes. So why is it important to look out for such things when you have stored gasoline? Each color of light has a different wavelength. Hence, a given disparity in the path length will cause constructive interference of certain colors, whereas other colors will not be observed because of destructive interference.

Because the oil film gradually thins from its center to its periphery, different bands of the oil slick produce different colors. Newsletter Get smart. Sign up for our email newsletter. Already a subscriber? Sign in. Thanks for reading Scientific American.

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