Care of Fish
Does charcoal float in water?
Asked in Science
Wood charcoal is heavier than water yet floats on water?
The only way that charcoal (whether of wood, animal, etc.) can float on water is if the total mass of the charcoal is less than the total mass of an equivalent volume of water. This means that the charcoal is not heavier than water, at least not an equal volume of water. If the charcoal was heavier than (an equivalent volume of) water, it would not float.
Asked in Metal and Alloys
How do you separate powdered charcoal from a mixture of copper oxide?
To separate powdered charcoal from a mixture containing copper oxide, just add water. Charcoal is considered quite a bit less dense than water and one set of tables gives the density as circa 400 kg.m-3 . Copper oxide is much more dense than water or charcoal. So the copper oxide will sink to the bottom and the charcoal will float to the top of the water. This can now be decanted and filtered leaving the charcoal on the filter paper which can be dried and to leave charcoal. Then with a separate filtration, the copper oxide and traces of water can be filtered and then dried.