Some examples are given in the following table. When the concentrations of reactants and products are variable, we can determine D G as where R is the universal gas constant, T is temperature, and C product , C reactant are the initial concentrations of the products and reactants. In other words, for more product to be created, this reaction is not spontaneous, and energy is required for the chemical reaction to occur. We can also use this equation for D G as a function of product and reactant concentrations to determine the equilibrium constant of a reaction. The rate and direction of a chemical reaction depends on the free energy, entropy, and concentration of the reactants and products as well as the temperature and pH of the system.
Chemical reactions progress in the direction of high to low energy.
We can estimate the direction of the chemical reaction, as well as the equilibrium concentrations of reactant and product, by examining the energy of the reactants and products. Look at the table of standard free energies for different chemical reactions. Molecular Cell Biology. Scientific American Books, Inc., New York Tobin, A. J. and R. E. Morel. 1997. Asking About Cells.