Molar Ratios

Find X

(460.5/X) x 100 = 100 - 16.3

then use that molar mass to calculate the number of waters

Pure Genius ,

I found difficulty incorporating the 16.3% into the method - but you just hit the hammer directly on the nail!

Ever Grateful, qazwsxedc

anytime

I've only started AS chemistry, but could you not do an empirical formula, calculation, but using percentages instead of mass? Or does the fact that it's organic mean that wouldn't work?

No I don't think so - if I think I know what you're suggesting - i.e. do it by element (Cu is 25%, O is 16%, H is 5% by mass?)

Not really. I mean, you know 16.3% is water, so 83.7% isn't water.

Divide 16.3 by 18 to get moles of water, and divide 83.7 by 460.5 (I think the 460.5 doesn't include the Mr of water) to get the moles of everything else.

Then simpify the ratio?

Lets try it:

16.3/18 = 0.9056
83.7/460.5 = 0.1817

divide by the lowest number

H2O: 4.98
[Cu(CH3COO)2]2.Cu(OH)2: 1

so yeah that does work