Chemistry · Ch 8 — Physical and Chemical Equilibrium
Physical and chemical equilibrium
Physical and chemical equilibrium
Equilibrium is a general idea, not one unique to chemistry. If two people of equal weight sit at equal distances on opposite sides of a see-saw's fulcrum, the see-saw stays level and stationary -- it is in equilibrium (Fig. 8.1). In a tug-of-war, if both teams pull on the rope with exactly equal force, the rope does not move in either direction -- again, a state of equilibrium (Fig. 8.2).
In a reversible chemical or physical process, equilibrium is reached at the particular stage where the rates of the two opposing changes become equal. At that stage, the concentrations (or amounts) of reactants and products stop changing with time -- but it would be a mistake to think of this as the system having simply stopped. The condition is not static, it is dynamic: both the forward and the …
What this figure shows. Two figures (children or weights) of equal weight sitting on opposite ends of a see-saw at equal distances from the central fulcrum, so the see-saw balances and stays level and stationary -- a simple mechanical picture of equilibrium as a balance of oppo …
What this figure shows. Two teams pulling on opposite ends of a taut rope. Both teams pull with equal force, so the rope (and the marker at its centre) stays stationary, illustrating equilibrium as a state where two opposing actions exactly cancel rat …