By: Anthoney Tetreault How to use a Crucible? By: Anthoney Tetreault

Using the Crucible Hold small amounts of chemicals Heating at high temperatures The lid covers the bowl so nothing escapes Keep oxygen out of the reaction

Techniques for using Crucibles The cover can be tilted slightly to let hot gases escape easily The crucible should be heated slowly With the Bunsen burner held at a distance at first Then brought in closer as the crucible gets warmer The crucible can be heated until it is red hot Bunsen burner is centered underneath the crucible The flame is turned up high and comes in contact with the bottom of the crucible

Techniques for using Crucibles Cont. Place hot crucible on wire gauze A cold surface may crack the crucible It will ruin your experiment Dirt, and paint, are easily fused onto the hot porcelain, changing its mass.

About Crucible Crucibles are very hot when you first put them on the wire Let them cool down to room temperature before weighing See if it is safe to weigh by bringing your hand over the crucible Feel for the heat to rise at first The crucible will be cool enough when you can let your hand barely touch the lid

Cleaning a Crucible Step 1 GENTLY SCRAPE RESIDUE LEFT THE MATERIALS USED IN YOUR EXPERIMENT FROM THE CRUCIBLE Step 2 FILL YOUR PORCELAIN CRUCIBLE WITH POTASSIUM BICARBONATE; YOU SHOULD HAVE ENOUGH BICARBONATE IN THE CRUCIBLE TO FILL PAST THE LINE OF THE REMAINING MATERIAL FROM YOUR EXPERIMENTS

Cleaning a Crucible Step 3 PLACE CRUCIBLE ON A BURNER. HEAT THE CRUCIBLE UNTIL THE BICARBONATE MELTS. HEAT IT UNTIL A LAYER OF RED POTASSIUM SALT APPEARS ON THE SURFACE. USING A MIXING ROD, STIR THE MELT A FEW TIMES. THE ENTIRE MELTING PROCEDURE SHOULD TAKE ABOUT ONE MINUTE. Step 4 REMOVE YOUR CRUCIBLE FROM THE FLAME. POUR OUT THE MELT. Step 5 RINSE THE CRUCIBLE IN HOT WATER. FOR PORCELAIN CRUCIBLES, USE A CLEAN CLOTH TO DRY THE SURFACE.

Works Cited http://www.files.chem.vt.edu/RVGS/ACT/lab/Experiments/crucible.html http://www.ehow.com/how_5045728_clean-crucibles.html http://wiki.answers.com/Q/What_is_a_crucible_and_how_is_it_used_in_a_laboratory