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Robert Krampf's Experiment of the Week |
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This Week's Experiment - #184 Flat Water |
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It is hurricane season here in Florida, but luckily this has been a very calm |
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season so far. We still have to be sure to be prepared, just in case. I |
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came across the idea for this experiment while reviewing some of the |
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emergency information. Often during hurricanes, the water supply is contamina |
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ted and it is necessary to boil your water before drinking it. All of the |
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information sheets say that this makes the water taste flat and they give |
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several different ways to "fix" the taste. To see how boiling changes the |
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taste, you will need: |
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a large steel or glass pot. Do not use aluminum or copper |
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water |
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stove |
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4 glasses |
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Fill the pot about half way with water and bring the water to a boil. Let it |
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boil for at least 4 minutes. Turn off the heat and let the water cool to the |
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point where you can comfortably put your finger into it. Be careful not to |
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burn yourself! Put some regular, unboiled tap water into one glass and label |
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it "unboiled." This will be our control, giving us something for comparison. |
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Put some boiled water into another glass and label it "boiled." Put some of |
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the boiled water into the third glass. We want to dissolve some air in this |
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glass of water. To do that, take the empty glass that you have left over and |
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hold it over the sink. Pour the boiled water from the third glass into the |
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empty one. You will get the best results if you hold the empty glass at |
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least a foot below the water glass, so that the water gets lots of air |
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bubbles mixed with it. Pour the water back and forth between the two glasses |
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at least 30 times. Label this glass "dissolved air" and place it with the |
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other two. Cover all three glasses and place them in the refrigerator to |
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cool. Once they are cool, taste each one. |
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What did you find? The first thing that I found was the the temperature of |
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the water makes a BIG difference. Cold water is much more pleasing than hot |
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water. Be sure that all three glasses are the same temperature before you |
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taste them. |
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The tap water should taste just like water, as you would expect. The boiled |
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water probably tastes strange, sort of "flat" or bland. The glass with the |
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dissolved air should taste much more like the tap water. Part of the taste |
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that we like in our water is the result of dissolved gases. I have searched |
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quite a bit and have found that some sources say this is due to dissolved |
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oxygen and others say it is dissolved carbon dioxide with gives the pleasing |
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flavor. I suspect that both gases contribute. The hurricane texts say that |
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you can fix the taste by either pouring the water back and forth as we did, |
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by letting it sit overnight (so it can absorb more of the gases), or by |
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adding a pinch of salt to cover up the "flat" taste. Personally, I find that |
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a tea bag and a bit of lemon does wonders for the taste. |
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Get volume 1 of the Experiment of the Week postings in book form! To order, |
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send $9.95, plus $3.00 postage and handling to: |
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Robert Krampf |
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PO Box 60982 |
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Jacksonville, FL 32236-0982 |
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Include your e-mail address and I will notify you when I get your order. |
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If you would like to be on the list, just send me an e-mail at [email protected], asking to be added to the Experiment of the Week List. |
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Check out our web site at: |
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http://www.krampf.com |
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From Robert Krampf's Science Education Company |
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4850 A1A South |
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St. Augustine, FL 32084 |
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(904) 471-4578 |
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