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My habit is putting the concentrations of each species into the ICE box. I like to use concentrations rather than moles so that I don't have to remember to do an extra step at the end of converting moles into concentrations.
When I use the ice table, I normally start with concentrations because I can directly calculate the equilibrium concentrations and plug them into the K expression to solve a problem. However, if you use moles, then you have to make sure to convert to concentrations later on, which you could possibly forget to do. Therefore, I think it's safer and more helpful to use concentrations.
I tend to just use concentrations because it makes it much easier to be able to solve for equilibrium constants. I would say that is the safer bet (to use concentrations over moles) because there is a chance that you may forget to convert moles to concentration when finding equilibrium constants.
I convert it to moles in the beginning but i think that would only be for Kc because since K is unitless when calculating Kp (pressure) i don't think it matter if you do bar or atm
It really depends on the type of problem. If you are given the moles and volume of an reactant or products, I use the concentration since its usually the initial concentration needed for ICE Box calculations. However, if I am already given at least one concentration at equilibrium for a reactant or product, I solve the ICE Box first and then divide every final concentration by the volume.
I typically put concentrations in my ICE boxes. This allows me to do the conversion from moles to concentration at the beginning of the problem rather than the end so I don't forget to do it.
Always use concentrations, as it is less work. When the reaction vessel is not 1L, you will have to do some more work to convert the provided concentrations to the amount of moles. Also, we are measuring changes in concentration, so using concentrations is more applicable.
I would strongly recommend putting concentrations in the ICE box, even though I know Sappling often uses moles. Using concentrations reduces the amount of steps you will need to do later, and decreases the likelihood you will make an error like forget to convert moles to molarity.
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