Question

How can specific heat be used to identify substances?

Answer 1

Specific heat is an intensive property (like density, color, etc.) that does not depend on the amount of a substance present. This allows substances to be identified using their specific heat.

Imagine an unknown metal of known mass is heated to a known temperature. The heated metal can then be placed into a sample of water for which the volume (and therefore mass since 1mL=1g) and temperature are known.

The amount of energy (Q) transferred to the water can be calculated by using the equation `Q_w=m_wC∆T_w` since the mass (m) and ∆T(temp change) can be measured.

This allows for a calculation of the C value for the metal since the head gained (Qw) of the water will equal the heat lost by the metal (Qm).

The C value for the metal allows the metal to be identified.

A listing of C values for metals can be found here:
http://www2.ucdsb.on.ca/tiss/stretton/database/Specific_Heat_Capacity_Table.html