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### ICE Box

Posted: Tue Nov 28, 2017 8:43 pm
When determining the change in pressure, how do you know whether the "x" will be positive or negative? What determines this?

### Re: ICE Box

Posted: Tue Nov 28, 2017 8:56 pm
If the reaction is going to the right then the products will gain some partial pressure so it will be a positive x value for the product and a negative x value for the reactants. The same is true for the opposite in which a reaction going to the left should have a negative x value for the products and a positive x value for the reactants.

### Re: ICE Box

Posted: Sun Dec 03, 2017 9:05 pm
If the question gives you the pressures for all of the substances in the reaction (both the reactants and products), calculate Q and compare Q to K. If Q > K then X will be negative for the products and positive for the reactants as the reaction favors the formation of reactants. If Q < K then X will be positive for your products and negative for your reactants as the reaction favors the formation of products.

### Re: ICE Box

Posted: Sun Dec 03, 2017 9:39 pm
You have to calculate Q first.
If Q < 1, then you subtract from the reactants as products are forming. If Q > 1, then you add to the reactants!