Energy In Food

 

What will we use for this experiment? (Continued from previous page)

 

We have decided that we will need a certain number of grams of water.  How is it possible to measure water in grams?  Usually we measure water in what units?  

Knowing that one liter of water has a mass of 1 kg, how much would we need to make one gram?  Think about the units and their prefixes.  In a kilogram there are 1000 grams.  In a liter there are how many milligrams? So, in order to get one gram of water, you can measure out how many milliliters (ml) of water? 

Since that is a very small amount of water and it would be difficult to measure any temperature changes in such a small quantity, we will use 25 ml of water (which also equals 25 grams, remember).  That's about half a test tube, which is a reasonable quantity.

What else do we need besides food and water for this experiment?  Now we need a way to get the energy out of the peanut so it can heat up the water. How can we do that? ...The answer is on the next page.