Answer:
4) Scientists know that reactions at chemical equilibrium will shift to regain equilibrium when affected by external factors, so scientists can use external factors to manipulate these chemical reactions into producing specific results.
Explanation:
Le Châtelier's principle states that changes in the temperature, pressure, volume, or concentration of a system will result in predictable and opposing changes in the system in order to achieve a new equilibrium state. Le Châtelier's principle doesn't say anything about reaction rates.
The idea of an industrial process is to obtain an specific product. So, you can apply changes into a system in equilibrium to produce more desirable product. A simple example is to decrease the concentration of products by removing them or increasing the concentration of reactants by adding them, so that, more product is produced and more reactant is used, and the equilibrium is reached again.
