How does the color of water affect its evaporation rate?
Question
My experiment consists of 3 bottles of water. I added blue food coloring to one bottle, and red food coloring to another bottle, and the last bottle of water i added nothing. I've noticed the bottle of water I added nothing to, is evaporating faster than the blue and red water. Why is this?
Color and Water Evaporation - Information from others
LKPete: The short answer is that the "color" of water has no effect on evaporation. But this is because water, by itself, has no color, instead only reflecting the sky (the ocean on a cloudy day will be as gray as the clouds). You might make a case for any substance within the water that gives it color (algea, chemicals, etc.) that might change the water's viscosity, and, therefore, the rate at which it evaporates. Good Luck!
Carlin Jamieson-Dolan: Different coloured objects absorb different amounts of heat. A black car for instance will get significantly hotter on the inside than a white car. Another reason the uncoloured water may be evaporating faster is because the food colouring chemical itself takes longer to evaporate. The colour of the dye may in fact have nothing to do with it.
Jessica: Your basic problem is whether the increased life of your roses when in coloured vases is due to temperature changes, or changes in bacterial growth. To see if it's the temperature, use all clear vases, but heat some of them a few degrees warmer to simulate the heat effect of the coloured glass. If the roses in the heated vases last longer or shorter, then the heat has an effect on either the rose stems or the bacteria. If not, it doesn't.
Then, you just need to see whether rose life is affected by vase colour, apart from the colour's effect on temperature, but I don't know how you would do that. You would have to make both both your coloured and clear vases maintain the same temperature, and if the rose life still varied between them, you could probably assume that the change was due to different frequencies of light entering the vases and affecting either the rose stems or the bacteria.
For your experiments, I suggest using distilled water to eliminate the possibility that heat or light frequency is affecting some component of your tap water.Good luck with your experiments.
p.s. I'm going to have to get some "tincture of iodine"!
Links to More Science Projects
Here's a compilation of all the pages with information from students who are conducting scientific color experiments.
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Does a bull really see red? Do bees have super vision?
Don't miss this page at Color Matters: How Animals See Color
