Inversion tube experiment to determine the specific heat capacity

INVERSION TUBE EXPERIMENT

A method used to determine the specific heat capacity of a substance is the inversion tube experiment. A hollow tube containing lead shot can be inverted multiple times, with the temperature of the lead shot measured after each inversion using a thermometer.

As the tube is inverted and the lead shot switches between the ends of the tube, the temperature rises. This is because the gravitational potential energy is converted into internal energy of the lead shot. Assuming no energy is lost to the surroundings or the tube, the loss in gravitational potential energy is equal to the gain in internal energy.

mcΔTc=mgLn=gLnΔT

Where c is the specific heat capacity (Jkg−1K−1), g is the acceleration under gravity (9.81 ms−2), L is the length of the tube (m), n is the number of inversions and ΔT is the temperature change (K).