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Heating Mantles

The two types of heating mantles used in the organic chemistry teaching labs are shown below. They are shown plugged into a Variac (in the back of the photo), since heating mantles are NEVER plugged directly into the outlet.

Heating Mantles

The heating mantle on the left is covered with fabric. It comes with a detachable cord, as shown in the photo below below on the left. This type of heating mantle is nice because it is pliable, and can move somewhat to accommodate different sizes of flasks. The problem with this type of mantle is that it is quite easily broken. The wires which go from the plug into the mantle have a very weak physical connection to the mantle. If they are held by the cord and swung around, or if they are stored in a mass of other such mantles and pulled forcefully from the pile, the wires will detach from the mantle. They cannot be re-attached. Please handle them with care.

The picture below shows 3 heating mantles of this type. The one on the left is a brand-new one; the other two have been in use in the labs. Chemicals spilled on the upper one caused the fabric to deteriorate and the heating wires are now bare; the one on the left is frayed from mistreatment. Again, handle these mantles with care and do not spill chemicals on them.

Old Heating Mantles

Because of the problems stated above for the fabric-style heating mantles, the organic chemistry teaching labs have mostly replaced them with rigid heating mantles. These new mantles are much more durable than the fabric mantles, though they are also more expensive. They fit a 100 mL round bottom flask perfectly, but smaller flasks may need to be wrapped with foil to encourage efficient heating. The rigid type of mantle can be filled with sand to form a sand bath, as shown below. This ability is a real advantage of this type of mantle. Sand baths provide uniform heating for any size small container, due to the much higher surface contact.

Heating Mantles with Sand

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