Because they matter. The usual way to write an equilibrium constant expression is to use the concentrations, but that only really applies to solutions.
For gasses, the partial pressure is a pretty good equivalent (technically, the fugacity should be used instead, but at the level I'm guessing you're at based on the question that's a pretty fine distinction). For solids and pure liquids, it's more complicated. In practice, there's going to be a dependence on the surface area, since the reaction will only take place at the surface (unless the liquid is also the solvent, in which case it takes place everywhere). However, for simplicity's sake, they're usually just assumed to have a concentration of unity (equivalent to leaving them out of the equilibrium constant expression entirely). In general, this works pretty well in most cases, with possibly an added factor to represent surface area if that changes dramatically from one run of the experiment to another (for example, if you finely powder the solid instead of just leaving it in a single compact chunk).
It tells whether products or reactants are favored at equilibrium
NO!!! A large Equilibrium Constant means that nearly all the reactants have been used up to reach the equilibrium. Conversely a small K(eq) indicates that equilibrium is reached when very little of the reactants have been used.
Favors the reactants.
The molarity of products is divided by the molarity of reactants
The concentration of reactants and products remain constant.
When a system has reached chemical equilibrium, the concentrations of the reactants and product remain constant.
It tells whether products or reactants are favored at equilibrium
It tells whether products or reactants are favored at equilibrium
It tells whether products or reactants are favored at equilibrium
At equilibrium the concentrations of reactants and productas remain constant.
At equilibrium the concentrations of reactants and productas remain constant.
NO!!! A large Equilibrium Constant means that nearly all the reactants have been used up to reach the equilibrium. Conversely a small K(eq) indicates that equilibrium is reached when very little of the reactants have been used.
No, the equilibrium constant is independent of concentration as long as the ratio of products and reactants remains as is. It can be effected by anything that would influence the ratio of products and reactants, such as changes in temperature or the addition of a catalysis.
It is the ratio of the concentrations of products to the concentrations of reactants.
It is the ratio of the concentrations of products to the concentrations of reactants.
It is the ratio of the concentrations of products to the concentrations of reactants.
Favors the reactants.