If you like us, please share us on social media or tell your professor. Consider building or adopting a Wikitext for your course like Prof. Dianne Bennett from Sacramento City College demonstrates in this video.
The concept that chemical processes may not evolve "to completion" and instead tend to stop mid-way results in an "equilibrium" where reactants, products and potentially intermediates might be present. Identifying the concentrations of these populations requires rigorous definition of new reaction parameters (e.g. the equilibrium constant).