How to heat metal sodium in order to melt it using an electric circuit?

Question

The apparatus that can be used are :
small coil of wire
voltmeter
switch
low voltage power supply
other standard equipment which may be found in a school/college laboratory is available

Answer 1

One question, what metal is the "small coil of wire" if it happens to be for example, iron, nichrome, platinum or something else with higher resistivity than sodium, you might be better off using the coil of wire as a heating element., say wrap it around a crucible and but the sodium inside, since the melting point is about 98C, you can even keep it coved with oil to prevent contact with the air. Actualy, even if the wire is copper, you _might_ still be better off using it as a heating element. Because sodium is fairly conductive and using it's own resistance for ohmic heating may take substantial current. The large current may mean more heat is generated in the wile leading to the sodium than in the sodium itself. But since the temperature does not need to be raised a great deal, either way might work.

Answer 2

Sodium is a metal, therefore it is conductive. If you connect your wire in series with the sodium by joining the ends of the wire to the sodium and connecting the wire to the power supply, with your voltmeter in parallel, if you turn on the switch, you will detect a reading on your galvanometer and before long, due to its low melting point (98 degrees) it will melt due to the heating effect of current flowing through it

Answer 3

Just pass a current directly through it and let ohmic heating do the trick.

One word of caution, do **NOT** do this in the open air. Sodium will ignite at room temperatures (which is why it's usually stored in a thin oil) and must be kept away from contact with oxygen.

HTH

Doug