Units for K

[Lizette Noriega 1H]

Why doesn't K have any units?

[EvanWang]

K is technically calculated using an attribute called the activity of a substance, and activity is unitless.

[sarahforman_Dis2I]

In addition, because the activity is equal to a constant multiplied by the concentration, and often times that constant is equal to one under ideal conditions, we can assume that the concentration values are values of the activity. As someone stated above, activity values do not have units.

[Diana Chavez-Carrillo 2L]

To go off of the previous responses, although units are omitted when we write K we write a C or P next to it which indicates the units we are using without necessarily writing them. The purpose of this is to make sure that it is clear whether we are calculating concentration or pressure. For Kc, it indicates that we are using molar concentration units. For Kp, it indicates that you are using partial pressure with atm or bar as your unit to find the total pressure. This is why it's important when writing K to specify if its Kc or Kp.

[DLee_1L]

K is just the ratio of the amount of product versus amount of reactant. So if the product is 20 M and the reactant is 5M at equilibrium the units (M) would cancel out and Kc would equal 4

[Catherine Daye 1L]

The equilibrium constant K is the ratio of reactants to products, and ratios don’t have units.

[ThomasNguyen_Dis1H]

Because it is a constant and is just a value used to look at the equilibrium of the reaction

[805373590]

Since k is a ratio constant the units of the products and reactants concentration cancel out making k a unitless constant.

[CynthiaLy4F]

K is unitless because it is the activities of products over the activities of reactants. Since activities do not have units, K will not have units.

[Tahlia Mullins]

The combination of K being a measurement of activity as well as the fact that it is a constant, means that it does not have ay units.

[McKenna_4A]

K is a ration, so all units cancel