K and Kc

[Jessy Ji 2J]

Hi,

When I am doing the textbook problems, many of them says refer table 5G.2. I noticed that there are two columns in the table one with K values and one with Kc values. I was just a bit confused on when should we use Kc and when should we use K?

[Vy Le 1G]

Hello Jessy,

We tend to use Kc when you are calculating with molar concentrations. I’m assuming for all other situations (ie. partial pressure), you can use K.

Hopefully this clarified!

[Michelle_Duong_3H]

Hello,

Kc specifies that your calculations involve molar concentrations (n/L). Kp would specify that your calculations involve partial pressures (atm, bar, etc.). I believe that the textbook's K refers to Kp. However, remember that the equilibrium constant itself does not have units because it represents the ratio of products to reactants.

Hope this helps!

[Qinyan Feng 1H]

Hi

For example, if it's a reaction involving only gases, and you are using partial pressure in your calculation, then you should use K (which is the same as Kp). You should use Kc when you use molar concentration in your calculation. Another thing we should remember is that when we use K (Kp), the unit should be 'bar'.

[cnyland]

Use Kc when dealing with only molar concentrations and K when dealing with anything else!

[Michael 1G]

K is a general symbol for a reaction equilibrium constant while Kc specifically is the equilibrium constant for an aqueous solution where concentrations are used for the calculations.

[Mario Prado 1K]

Hello,

Kc is when we're specifically talking about molar concentrations while K is just the basic symbol for equilibrium constants.

Hope this helps.

[Samir Panwar]

K represents the equilibrium constant, while Kc is used when we are given molar concentrations.

[Amine Adlouni 1L]

Kc is an equilibrium constant specifically for concentrations, whereas K is a general variable for equilibrium constants.

[Bobak Pourrahimi 2L]

Kc is specific towards molar concentrations, K is for any unit, and Kp is particular to partial pressures.

[emmakvarnell]

K is just a general term for the equilibrium constant, but Kc specifies the equilibrium constant to when you are solving for concentrations.

[Mya_Chiarappa_2C]

K is the more general form of the variable, while Kc is used to specify that it is based on molar concentrations, rather than partial pressures.

[Cindy Vo 3E]

K is the general form of the equilibrium constant, which could mean concentration or partial pressure. Kc is equilibrium constant specific for concentrations.

[Amanda Pineda 3H]

Hi when you see just K, it refers to the equilibrium constant for partial pressure but when you see Kc, it refers to the equilibrium constant for concentration/molarity.

[905767718]

The Kc concentration means that it's the equilibrium constant for solutions that utilize aqueous solutions. Therefore if you see the problem you're solving uses aqueous solutions to describe the molecules in the reactions or you use M, then you should use the Kc.

[Polo Morales 3C]

Hello! K is basically the term that is used for any equilibrium constant. Kc is specifically the equilibrium constant dealing with molar concentrations. Hope this helps!

[Monse Mata 3D]

We use Kc when we are dealing with only molar concentrations and K, as others said already, refers to Kp which is used when dealing with partial pressures.

[Caitlyn Lo 2F]

Kc is used when using molar concentrations, Kp is used when using partial pressures, and K is just the basic symbol for equilibrium constants