Water in Butter
Carefully weigh a clean, dry aluminum dish, place in it about 2 gms. of butter, and weigh again. Record the weights. Place the dish containing butter in the water oven for 5 or 6 hours and then weigh. The loss in weight represents the water in the butter. Calculate the per cent of water. Care must be taken to get a representative sample of the butter to be tested; preferably small amounts should be taken with the butter trier from various parts of the package.
Experiment No. 3
Ash in Flour
Place the porcelain dish containing flour from the preceding experiment in a muffle furnace and let it remain until the organic matter is completely volatilized. Cool, weigh, and determine the per cent of ash. The flour should be burned at the lowest temperature necessary for complete combustion.
Experiment No. 4
Nitric Acid Test for Nitrogenous Organic Matter
To 3 cc. of egg albumin in a test tube add 2 cc. of HNO3 (conc.) and heat. When cool add NH4OH. The nitric acid chemically reacts upon the albumin, forming yellow xanthoprotein. What change occurs in the appearance of the egg albumin when the HNO3 is added? Is this a physical or chemical change? What is the name of the compound formed? What change occurs on adding NH4OH?