We're going to try to help you with your problem, but I think we're going to face significant problems. Maybe its worth taking point by point.
I'm doing an experiment where I compare certain chemicals with each other. I will dissolve each chemical in water.
That is clear and easy to understand.
Now as to my question: Will I have to take the dissolubility into consideration?
I'mgoing to have to ask you to rigidly define "dissolvibility", I don't recognize this word.
Let's say I have two different chemicals, one chemical can dissolve in water without problems and the other can dissolve into water moderately.
We generally don't describe things in such general terms, and it makes your whole question more difficult. For example, according to Wikipedia, table sugar (sucrose) dissolves at 2000g/L and table salt dissolves at 359 g/L. This is a more useful way of comparing the solubility of two compounds in water.
Can I for example dissolve 20 grams of each chemical into water now
See, for my examples above, you can dissolve 20g of each in water. Its just that it takes more water to dissolve sodium chloride instead of sucrose. So your question really isn't clear.
or do I have to take the dissolubility into account?
Again, I don't know what you mean, unless you're trying to take the various solubilities into account. But without the volume of water, we can't be sure, it might be significant, it might not.
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