## Concentrations of products/reactants

Miriam Sheetz 2B
Posts: 64
Joined: Fri Sep 28, 2018 12:25 am

### Concentrations of products/reactants

Is the equilibrium constant K the ratio of the initial or equilibrium concentrations of the products and reactants?

Elisa Bass 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Concentrations of products/reactants

It is a ratio of the equilibrium concentrations.

marisaimbroane1J
Posts: 69
Joined: Fri Sep 28, 2018 12:23 am

### Re: Concentrations of products/reactants

Since K is the equilibrium expression, you use the concentrations at equilibrium. The initial concentrations can be used to do other calculations like with weak acids and bases.

Ian Marquez 2K
Posts: 66
Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 2 times

### Re: Concentrations of products/reactants

K is the equilibrium constant so the numbers you use are the equilibrium concentrations of the products and reactants. This tells you that this ratio will be approached when a reaction reaches equilibrium from its initial concentrations.

Alexa Tabakian 1A
Posts: 38
Joined: Fri Sep 28, 2018 12:20 am

### Re: Concentrations of products/reactants

Q would be anything other than equilibrium, and K is the equilibrium.

Anna O 2C
Posts: 98
Joined: Fri Sep 28, 2018 12:19 am

### Re: Concentrations of products/reactants

Adding on, K is referring to the concentrations held to the specific power and ratio as stated in the balanced equilibrium equation given in the problem. Knowing the concentrations won't do you any good if they aren't held to the correct power within the fraction for K.

Felicia1E
Posts: 31
Joined: Fri Sep 28, 2018 12:22 am

### Re: Concentrations of products/reactants

It also matters if it's Kc or Kp. While Kc does refer to the ratio of concentrations to their respective powers of products and reactants, Kp will refer to the ratio of partial pressures to their respective powers of products and reactants.