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The main thing to remember here is whether the H2O is being used in the reaction or is just passive as a solvent. Most of the times when it is present as a gas, that is being formed as a product or is reacting as a reactant. When it is a liquid it is usually used as a solvent, so it is not involved in the reaction and is thus not used in the equilibrium calculations.
When water is considered a liquid (essentially the solvent in the equation), the concentration of liquids does not change significantly to say it has changed in cc. However, when water is considered a gas, it is variable and can change.
Liquids and solids are not included because liquids tend to be in excess and remain virtually unchanged (and therefore cancel out in the numerator and denominator when calculating K) and solids don't have a concentration. Gases are included, and therefore H2O as a gas counts.
If H2O is shown as a gas, you do not omit it from your ice table. It H2O is a liquid and is used as a solvent, you would not include it because it is in excess and the concentration of H2O does not change in the reaction.
We do not exclude any gases. We will only exclude H2O when it is in liquid form. All liquids and solids are excluded because they do not have concentration. All gases and aqueous solutions will be included in the equilibrium constant/expression.
Hi! The rule is that in general, gases are always included no matter which molecule, and liquids and solids should always be excluded no matter which molecule. Even though H2O may typically be seen in its liquid form, if its in a gas form it should be included.
We don't include solids or liquids when solving ICE tables. When water is a gas, I believe we include it in the ICE table because the partial pressure of the gas will affect the overall equilibrium. Please correct me if I'm wrong!
If H2O is acting a solvent, then they are not included in the ICE table since the concentration doesn't change from reactant to product. If H2O is in its gas phase, then it is included in the ICE table.
Hello! It is crucial to remember that when you are completing your ICE box that you include only aqueous solutions and ages. Hence, if H2O is expressed to be. a gas, then you should include it in the ICE box, however, if it was not, you would not include it.
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