K units

Donna Nguyen 2L
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

K units

Why are units omitted when calculating K?

Hui Qiao Wu 1I
Posts: 56
Joined: Fri Aug 30, 2019 12:16 am

Re: K units

Explaining in a non-chemistry way, K is the ratio of products over reactants. And ratios are just numbers; they don't have units.

Eunice Nguyen 4I
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

Re: K units

K is a unitless quantity, because it's just a ratio of product over reactants. This also goes into the concept of activities (but that hasn't been really gone over in depth yet)

Justin Sarquiz 2F
Posts: 106
Joined: Fri Aug 30, 2019 12:15 am

Re: K units

The equilibrium constant is actually the activity of the product divided by the activity of the reactant. Calculating the activity is its own separate equation, but in that equation the units actually cancel. Therefore, the activity of the products and reactants have no units making K have no units too.

Jasmine Vallarta 2L
Posts: 102
Joined: Sat Aug 17, 2019 12:18 am

Re: K units

K is a constant

Christine Honda 2I
Posts: 116
Joined: Sat Sep 14, 2019 12:17 am

Re: K units

For the purpose of this class, K is unitless. But in higher classes, it refers to the "activity" of the reactants and products.

BritneyP- 2c
Posts: 101
Joined: Sat Sep 14, 2019 12:15 am

Re: K units

When you are looking for K is is molarity over molarity, which can cancel out all units. And if it doesn't cancel out all units, imagine the reactants changing to products or products changing to reactancts as activity, and activity is unitless.

Rohit Ghosh 4F
Posts: 99
Joined: Thu Jul 25, 2019 12:17 am

Re: K units

K is simply a ratio not a unit of measure

Jasmine Fendi 1D
Posts: 108
Joined: Sat Aug 24, 2019 12:15 am

Re: K units

K actually measures the activity of the reaction. For this class, I think we omit the units for simplicity

AngieGarcia_4F
Posts: 120
Joined: Thu Jul 25, 2019 12:17 am

Re: K units

I think it's because K is an activity and activities don't have units.

205405339
Posts: 77
Joined: Thu Jul 11, 2019 12:16 am

Re: K units

K is just a number that is used to show the ratio of products to reactants. I dont think K is ever used in equations so it doesnt need units anyways