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Water in K constant

Posted: Thu Jan 23, 2020 10:16 am
by Sanjana Borle 2K
Is water included in the K constant expression if it is a gas? Is it only not included when it is a solvent?

Re: Water in K constant

Posted: Thu Jan 23, 2020 10:49 am
by Ally Huang- 1F
Yes, water is included in the K constant if it is a gas because gasses can be written as a concentration and it is not the solvent. If it is a liquid it will not be in the K constant expression.

Re: Water in K constant

Posted: Thu Jan 23, 2020 11:40 am
by kristi le 2F
water is not included in the K constant when it is a solvent because it is viewed as pure. Liquids and solids are not included in the K constant since their concentrations do not significantly change.

Re: Water in K constant

Posted: Thu Jan 23, 2020 11:58 am
by Abby Soriano 1J
kristi le 2F wrote:water is not included in the K constant when it is a solvent because it is viewed as pure. Liquids and solids are not included in the K constant since their concentrations do not significantly change.


To add to this, since water is the solvent, it will be in excess and so its concentration will not experience a significant change. This is why when water is in its liquid form, we don't include it in the K expression.

Re: Water in K constant

Posted: Thu Jan 23, 2020 12:48 pm
by Ying Yan 1F
If water is in its gas phase in the reaction, then you do include it in your equilibrium ratio.

Re: Water in K constant

Posted: Thu Jan 23, 2020 12:51 pm
by Simon Dionson 4I
Water is only not included if it is a solvent (liquid) or a solid.

Re: Water in K constant

Posted: Thu Jan 23, 2020 12:51 pm
by Shivam Rana 1D
water is included in the Kp expression if it is a vapor.