# TBR-Gen Chem-Equilibrium Problem

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#### DrMula

##### Full Member
5+ Year Member

Which of the following Keq values is bigger? (1.95atm^-1) or (2.1 x 10^4 atm-1).

At first I thought that 2.1 x 10^4 atm^-1 would obviously be bigger, but then I saw that it was "atm^-1", and thought that meant that its actually 1/(2.1 x 10^4 atm), so in actuality 1/(1.95atm) is greater than 1/(2.1 x 10^4 atm). BUT turns out that's wrong.....

Does the "atm^-1" mean that the whole value is 1/(#units) or does it mean that only the "atm" is 1/atm (so units goes to denominator and # stays in the numerator)? I read the explanation in the book but it doesn't address this aspect...

I hope I made my question clear...thanks!

#### Czarcasm

##### Hakuna matata, no worries.
5+ Year Member
Yeah, it's the unit themselves that go in the denominator. So in your example: 2.1 x 10^-4 atm-1 is equivalently rewritten as: 2.1x10^4/atm (not 1 / 2.1x10^ atm).

The units are a little bit odd and less intuitive for Keq expressions, but regardless, anytime units are expressed with a -1 symbol, it indicates that it goes in the denominator.

#### DrMula

##### Full Member
5+ Year Member
Yeah, it's the unit themselves that go in the denominator. So in your example: 2.1 x 10^-4 atm-1 is equivalently rewritten as: 2.1x10^4/atm. The units are a little bit odd and less intuitive for Keq expressions.
So is that a general principle when dealing with units raised to the negative 1 power? (units go to denominator, # will stay on top)...or is this a technique specifically used for Keq expressions? Like for example 4meters^-1 would be 4/meters or 1/4meters?

#### Czarcasm

##### Hakuna matata, no worries.
5+ Year Member
So is that a general principle when dealing with units raised to the negative 1 power? (units go to denominator, # will stay on top)...or is this a technique specifically used for Keq expressions? Like for example 4meters^-1 would be 4/meters or 1/4meters?
Just updated my previous post. It would simply be 4 per meter or 4/m.

#### DrMula

##### Full Member
5+ Year Member
Gotcha, I really appreciate the help--thanks!

#### DrMula

##### Full Member
5+ Year Member
Just updated my previous post. It would simply be 4 per meter or 4/m.
Gotcha, I really appreciate the help--thanks!