C) The purpose is to determine the empirical formula of a metallic oxide. D) Pre Lab Questions:
After heating the metal, the crucible and contents should mass less than it did before it was heated. This is because heating the crucible may rid of other residue that was left in it; bringing it a to a constant mass. A yellow flame will deposit soot on the crucible. This would be a problem because the soot left on the crucible would vary from our constant mass and cause our mass to be inaccurate. We have to heat the crucible first without any material in it because we want to have the crucible heated at a constant weight. The chemical make-up of the compound being produced will be magnesium oxide. You must carefully sand the outside of the magnesium ribbon to remove any oxide coating.
Ring support clamped to a ring stand
F) Safety Precautions/ Waste Disposal:
Wear goggles and aprons at all times.
Tie back hair and roll up sleeves.
Handle crucible with proper tongs.
Do not look directly at the burning metal!
Do not stir or otherwise disturb the product in the crucible. When finished, discard the entire contents of the crucible into a designated beaker provided by the instructor. Keep hot equipment at safe distances and do not touch till it is has cooled for the instructed amount of time.
Place a crucible on a clay triangle balanced on a ring support clamped to a ring stand. Note: Don’t use the lid to the crucible.
Place a lighted burner under the crucible and adjust the ring support so that the crucible is in the hottest part of the two cone blue flame. Note: It is important to get the tip of the inner cone directed at the bottom of the crucible. The hottest part of the flame is the inner cone of the flame. Heat the crucible so that the bottom...