### Understanding Q

Posted:

**Wed Jan 08, 2020 10:23 pm**When solving for Q do we omit solids and pure liquids, like when solving for K?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=123&t=55751

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Posted: **Wed Jan 08, 2020 10:23 pm**

When solving for Q do we omit solids and pure liquids, like when solving for K?

Posted: **Wed Jan 08, 2020 10:28 pm**

Yes; when solving for Q, you write the expression in the same exact way you would for K, omitting pure liquids and solids. The central difference between Q and K is that K represents the value at equilibrium, while Q is the ratio of products to reactants at any time during the reaction. But you would solve for the expression and value of Q in the same exact way.

Posted: **Wed Jan 08, 2020 10:33 pm**

Yes, solving for Q is the same way you would solve for K

Posted: **Wed Jan 08, 2020 10:59 pm**

Q is just ratio of the products and reactants when not in equilibrium, but is calculated the same way as K.

Posted: **Wed Jan 08, 2020 11:41 pm**

Just solve Q the way you would for K. K is at equilibrium and Q is at any time.

Posted: **Thu Jan 09, 2020 8:34 am**

Yes, you would still omit solids and pure liquids. You also emit these when making an ICE table.

Posted: **Thu Jan 09, 2020 9:34 am**

Hiba Alnajjar_2C wrote:Yes; when solving for Q, you write the expression in the same exact way you would for K, omitting pure liquids and solids. The central difference between Q and K is that K represents the value at equilibrium, while Q is the ratio of products to reactants at any time during the reaction. But you would solve for the expression and value of Q in the same exact way.

Thank you!

Posted: **Thu Jan 09, 2020 9:55 am**

Correct. We perform the same calculation procedure when solving for Q and K.

Posted: **Thu Jan 09, 2020 10:01 am**

Yes. Q and Kc are solved the completely same way. Q is just to tell if the reaction is at equilibrium or not.

Posted: **Thu Jan 09, 2020 11:44 am**

They're solved exactly the same way.

Posted: **Thu Jan 09, 2020 11:48 am**

Yes, you solve for Q the same way you would solve for K.

Posted: **Thu Jan 09, 2020 3:34 pm**

You solve for Q the same way you solve for K.

Posted: **Thu Jan 09, 2020 3:54 pm**

Q tells what point the reaction is at in relation to K, therefore it is solved the same way as K.

Posted: **Thu Jan 09, 2020 4:48 pm**

Yes you can solve Q the same way as you would solve K.

Posted: **Thu Jan 09, 2020 7:06 pm**

do you omit pure solids and liquids while solving for K too?

Posted: **Sun Jan 12, 2020 10:34 pm**

805097738 wrote:do you omit pure solids and liquids while solving for K too?

Yes, that is correct.

Posted: **Sun Jan 12, 2020 10:51 pm**

Yes, solving for Q is the same thing as solving for K in terms of calculations (just that the reaction might not have reached equilibrium yet).

Posted: **Sun Jan 12, 2020 11:16 pm**

Q is solved the same way as K, Q is just not at equilibrium.

Posted: **Sun Jan 12, 2020 11:49 pm**

Q is calculated the same exact way as K just it can be anytime during reaction not just during equilibrium

Posted: **Mon Jan 13, 2020 12:37 pm**

To solve for Q we have to be given the values of each product and reactant, correct?