H2O in K equation

[Kayley Steele 3D]

In the examples in lecture we left H2O out of the equation for K because we consider the concentration unchanged but in the book the H2O concentration is included. Which should we do?

[Amy Xia 1J]

I think we are supposed to follow what the professor said in class. When H2O is in the liquid state and act as a solvent, we should leave it out when calculating K since the change in solvent concentration is insignificant.

[Myra Goraya Dis 2E]

we ignore all pure substances in the k equation as their concentration stays the same, therefore, since h2o is a pure liquid, we would not consider it to be part of the k equation.

[Trang Tran 1H]

Hi. I remembered the Professor said that since the H20 liquid before the reaction and after the reaction is approximately equal so it will cancel each other out in the Kc equation. So it is unnecessary to include it in the Kc formula.

[Caleb_Mei_1J]

Hey there!

Although H2O may be present in the chemical reaction, it should not be included in the equilibrium constant formula since the concentration of water does not change.

I hope this helps!