Answer to Question #96046 in General Chemistry for brooke

Question

If a student attempts to identify an unknown compound by method used in this experiment. She finds that when she heated a sample weighing 0.4862 g the mass went down appreciably, to 0.3067 g. When the product was converted to chloride, the mass went up, to 0.3380g.

Answer 1

The description of the experiment allows no identification of the unknown compound. We should have some information as for the nature of the compound and a number of elements in it. First stage is quite uncertain: what kind of matter was lost under the heating (water, carbon dioxide etc.)? Or maybe, it was total decomposition of the compound? Was it binary compound or not? Let us suppose that it was some metal compound and it was decomposed up to the pure metal and then it was chlorinated. Thus, according to the rule of equivalent, the molar mass of this metal should be:

$E_M=\frac{0.3067g*35.5g/mol}{0.3380g-0.3067g}=348g/mol$

There is no such metal. And it is also not possible to get any relevant information from this experiment.