Lithium…

Lithium is the third element on the periodic table and first metal. It sits in Group I with the other reactive metals such as sodium and potassium. It is soft, low density and highly reactive – although the least so of the alkali metals.

Apparently they used to put lithium citrate into 7-Up although they no longer do. Lithium salts are used to treat depression so I wonder if they were added to make 7-Up a ‘tonic’ similar to the original recipe for Coca-Cola. In the following video a lump of lithium is dropped into some 7-Up to see what will happen. It is not especially dramatic but they do talk about lots of chemistry that you should understand (pH, indicators, etc.)

Questions…

1. What would you expect the pH of a fizzy fruit drink like 7-Up to be?
2. What is an indicator?
3. What two gases are given off when the lithium is dropped into the drink?
4. What would you expect the pH of lithium hydroxide to be?
5. What acid would you use to make the salt, lithium citrate?
6. How does temperature usually affect the rate of a reaction?
7. What other changes can you make to alter the rate of a reaction?