bigger/larger number of mole(s)

I keep re-reading this sentence and it just sounds so wrong to me. I am not quite sure which part is wrong but I am sure that there is something wrong with it. Am I supposed to use the word bigger or larger? and is moles supposed to be plural or singular?

"In the empirical formula, there would be a bigger number of moles of water per mole of anhydrous salt than if the compound had not spilled. "

Solution 1:

A much better alternative would be greater:

In the empirical formula, there would be a greater number of moles of water per mole of anhydrous salt than if the compound had not spilled.

Or, even better:

In the empirical formula, there would be more moles of water per mole of anhydrous salt than if the compound had not spilled.

As for moles that should indeed be plural. A mole is a unit just like any other, so you would say N moles just like you would say N meters. In fact, given that a mole is, by definition, ~ 6.02e10 somethings, it is even more reasonable to have it pluralized than other units.