a chemical reaction occurs when reactant particles

We conclude that the supposed situation is impossible and that the catalyst must accelerate the forward and backward reactions equally.'

A cycle has therefore been completed for which the net effect has been the isothermal conversion of heat energy into work, and a perpetual motion machine of the second kind has been found. Heat δq is now extracted from the surroundings, which must warm the system back to the ambient temperature. We then remove the catalyst and the equilibrium shifts back. This heat is used to run a machine, and thus do work, cooling the system back to its original temperature in the process. We first allow equilibrium to be reached without the catalyst.and then add the catalyst, and heat δq is produced as the equilibrium is shifted. If we suppose further that the reaction produces heat q when it occurs, then a violation of the second law would be possible. The position of equilibrium would therefore shift to the right, by the law of mass action.

In its presence, the sum of the forward rates would clearly be larger than otherwise, while the backward rate would be unchanged. 'Suppose that, as indicated in the figure, the catalyst affects only the forward reaction. But shift-equilibrium cycles violate the second law of thermodynamics and thermodynamicists prohibit them: Obviously, the net work involved in the quasistatic cycle is zero (the work lost in concentrating is compensated by the work gained in deconcentrating).Ĭoncentrating implies shifting the chemical equilibrium in one direction deconcentrating implies shifting it in the other and closing the cycle.

A chemical reaction occurs when reactant particles