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### Kc & Kp

Posted: Thu Jan 16, 2020 10:18 pm
How do you know when to use Kc or Kp when dealing with gasses? For example, in problem 5I.17 we use Kc instead of Kp, why?

### Re: Kc & Kp

Posted: Thu Jan 16, 2020 10:33 pm
I think we use Kp when all of the reactants and products are gases.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 10:29 am
It depends on the information we’re given. For 5I.17, the problem gives us Kc so we have to use that.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 10:38 am
I don't think it really matters when the question does not specify which to use. The calculations are the same.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 3:23 pm
Can we just use K and not specify Kc or Kp? Or would we be marked down?

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 3:41 pm
gabbymaraziti wrote:Can we just use K and not specify Kc or Kp? Or would we be marked down?

I don't think you'll be marked down for using K.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 3:42 pm
gabbymaraziti wrote:Can we just use K and not specify Kc or Kp? Or would we be marked down?

I feel like they won't care on the test. But it can't hurt to take a look at the units and add the C or P.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 4:03 pm
You can tell which one to use by what's given in the question; if the values are given in brackets, then you know the values are concentrations rather than partial pressures and you should use Kc.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 4:04 pm
Kc is when the numbers given are concentrations while Kp is when the values are partial pressures.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 4:07 pm
Are the calculations the same regardless of whether its concentration of partial pressure?

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 4:59 pm
We use kc when we are dealing with concentrations but we only use kp when we are dealing with partial pressures of gases.

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 8:42 pm
Is it possible for there to be an equation with both gaseous particles and aqueous solutions? How would we go about solving this? Would we use a combination of Kc and Kp?

### Re: Kc & Kp

Posted: Fri Jan 17, 2020 9:32 pm
Elizabeth Harty 1A wrote:Are the calculations the same regardless of whether its concentration of partial pressure?

i believe the calculations are the same so i think its okay as long as you account for any differences in units or something