Chemistry -equilibrium expression

But what does the equilibrium constant tell us about the reaction?
The higher the value of the equilibrium constant the greater the amount of product that is formed. In other words the greater the value of K_c the greater is the extent to which the reaction moves to the right. For values of K_c of less than 10 ^-4, significant amounts of reactants are present at equilibrium and little product is formed. While for values greater than 10 ⁴, the formation of product is favoured. For values of K_c in between these, significant amounts of product and reactants remain at equilibrium.
The K_c values of three reactions are given below.
1) K_c = 2 X 10 ¹⁰,
2) K_c = 0.34
3) K_c = 2 X 10 ^-12,
The only reaction out of the three that favours the formation of products is 1). It has a significantly higher "K_c" value

Equilibrium expression
So many important reactions involve equilibria that scientists have sought to find a mathematical expression they can apply in order to provide the right conditions to best manipulate these reactions. A mathematical expression was found that gives a constant value, at the same temperature, when the system has reached equilibrium. The expression is given below and is known as the *reaction quotient* or equilibrium expression. Now the reaction quotient has different values as the reaction proceeds, depending on the mixture of substances in the reaction vessel. Is is only when the system reaches equilibrium that the value of the reaction quotient remains constant at a value known as the equilibrium constant (K_c).
K, the reaction quotient, is equal to K_c only when the system has reached equilibrium.	*Click* to see the equilibrium expression for the combustion of ethane form from the equation given on the left. The equilibrium expression is different for each equation. For example take the same reaction as on the left but with different coefficients in front of the reactants and products. The equilibrium expression will be as shown below Therefore, it is important when the value of an equilibrium constant is quoted that the equation is also specified.
But what does the equilibrium constant tell us about the reaction? The higher the value of the equilibrium constant the greater the amount of product that is formed. In other words the greater the value of K_c the greater is the extent to which the reaction moves to the right. For values of K_c of less than 10 ^-4, significant amounts of reactants are present at equilibrium and little product is formed. While for values greater than 10 ⁴, the formation of product is favoured. For values of K_c in between these, significant amounts of product and reactants remain at equilibrium. The K_c values of three reactions are given below. 1) K_c = 2 X 10 ¹⁰, 2) K_c = 0.34 3) K_c = 2 X 10 ^-12, The only reaction out of the three that favours the formation of products is 1). It has a significantly higher "K_c" value
Exercises Lets see how we can use the mathematical expression of equilibria to calculate and predict products and reaction conditions. Continue