Units for K
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 105
- Joined: Wed Sep 18, 2019 12:15 am
Re: Units for K
K is technically calculated using an attribute called the activity of a substance, and activity is unitless.
-
- Posts: 109
- Joined: Sat Aug 17, 2019 12:18 am
Re: Units for K
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.
-
- Posts: 122
- Joined: Fri Sep 28, 2018 12:18 am
Re: Units for K
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.
Re: Units for K
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
-
- Posts: 104
- Joined: Wed Sep 11, 2019 12:16 am
Re: Units for K
The equilibrium constant K is the ratio of reactants to products, and ratios don’t have units.
-
- Posts: 102
- Joined: Fri Aug 30, 2019 12:17 am
Re: Units for K
Because it is a constant and is just a value used to look at the equilibrium of the reaction
Re: Units for K
Since k is a ratio constant the units of the products and reactants concentration cancel out making k a unitless constant.
-
- Posts: 103
- Joined: Sat Jul 20, 2019 12:16 am
Re: Units for K
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.
-
- Posts: 105
- Joined: Thu Jul 25, 2019 12:15 am
Re: Units for K
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.
-
- Posts: 115
- Joined: Sat Aug 24, 2019 12:18 am
Return to “Equilibrium Constants & Calculating Concentrations”
Who is online
Users browsing this forum: No registered users and 7 guests