The Scientific Method

So it came up this week that Tex has the Scientific Method as a part of his Scouting requirements, and although they get a healthy dose of it from The Mythbusters I'm always happy to take opportunities to use it in real life. So. Noodle is a nut for "experiments". This mostly just means mixing stuff together, and it doesn't even have to be sciencey (yes, it's a word, so hush) stuff, it can just be bubble bath and water. But on this particular day he wanted to repeat the experiment of the day before by mixing baking soda with various liquids to see which ones could make it bubble the most. He though chocolate and strawberry syrups mixed together had a good chance at the title. So we chose five liquids: the syrup mixture, fresh lemon juice, pasteurized OJ, honey, and filtered water. Noodle helped set up five separate samples of baking soda, and Tex joined in at this point to help me use litmus papers to test each liquid. The fresh lemon juice got the biggest reaction, turning the litmus paper a dark red almost immediately. Next on the list was the OJ, while the syrups, honey, and water all appeared to be rather neutral. We devised a system to rate the reactions, listing a "1" as no reaction, a "2" as a mild bubbling, and a "3" as a very fizzy reaction. After adding water to one sample of baking soda and recording a "1" reaction, we dipped litmus paper in the solution and it immediately turned a deep bluish-green.
Then the real fun started! The honey and syrups had to be thinned with water after our initial attempts resulted in little baking soda-covered balls of viscous liquid, but still rated as "1" reactions. The pasteurized OJ was rated a "2" for its light fizzing. The lemon juice was the clear winner with a big, bubbling foam that threatened to overtake its container! Then Tex and I wondered if fresh orange juice would have a different reactions than store-bought, so I grabbed what I thought was an orange and sliced it open only to find that it was really a grapefruit. Oops. Well, no matter, the Mythbusters make mistakes all the time, so we decided to include fresh grapefruit juice in our sample, too. We then squeezed some fresh OJ and tested both with litmus paper. The color of the litmus paper dipped in grapefruit juice was quite as dramatic as the lemon. The orange juice was less so, but more acidic than the pasteurized variety. Tex and I compared the blue base paper with the red lemon paper and noted that the biggest reactions came when combining the substances that had the most dramatic color changes, and from that he predicted that the grapefruit juice was going to have the biggest reaction of the two new liquids, but that the fresh OJ would have more of a reaction than the store-bought. And boy was he right! Noodle couldn't get over the fizz of the grapefruit juice and had a blast mixing it with baking soda, then mixing the lemon and grapefruit juices and adding them together. Two happy guys. :-)