Question

Exergonic and Endergonic Reactions What would happen if you rapidly shake a bottle of sand? How does this demonstrate the first law of thermodynamics? Free energy Energy released to surroundings Reactants (marble at top) Products (marble at bottom of hill)

Answer 1

If we put the sand in a bottle which have insulated walls. Insulated walls do not allow the heat energy to release outside. Insulated wall makes closed system.

When we rapidly shake the sand in bottle, then there is found increase in a temperature of the sand. Because the rapidly shaking of sand will generate friction with the wall. The friction generates mechanical force. The mechanical force is converted to heat energy. This leads to increase the temperature of sand.

According to first law of thermodynamics, the total energy of a closed system remains constant. The energy can be converted from one form to another. In our case, the mechanical energy is converted into heat energy. But the energy inside the bottle remains constant.