Yahoo Answers: Answers and Comments for What's the molecular formula of a compound with 52% C, 3.15% H, 44.4% Cl if the formula weight is 320g/mol? [Chemistry]
Copyright © Yahoo! Inc. All rights reserved.
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
From nandemonai
enUS
Sun, 24 Dec 2006 00:18:53 +0000
3
Yahoo Answers: Answers and Comments for What's the molecular formula of a compound with 52% C, 3.15% H, 44.4% Cl if the formula weight is 320g/mol? [Chemistry]
292
38
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
https://s.yimg.com/zz/combo?images/emaillogous.png

From sahsjing: First, you need to find molar ratio.
C: 320...
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
Sun, 24 Dec 2006 08:41:05 +0000
First, you need to find molar ratio.
C: 320(.52/12) = 14 mol
H: 320(.0315/1) = 10 mol
Cl: 320(.444/35.45) = 4 mol
Therefore, the molecular formula is C14H10Cl4

From claudeaf: OK....you've done the first step, by looki...
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
https://answers.yahoo.com/question/index?qid=20061224001853AAV1LQZ
Sun, 24 Dec 2006 08:40:39 +0000
OK....you've done the first step, by looking at 100g
Now, the second step is to convert each element to no of moles, by dividing mass by molar mass:
C: 52 / 12 = 4.33 mol
H: 3.15 / 1 = 3.15 mol
Cl: 44.4 / 35.5 = 1.25 mol
Now, divide all mol by the smallest quantity, which in this case is that of Cl (1.25).
C: 4.33 / 1.25 = 3.464 approx equal to 3.5
H: 3.15 / 1.25 = 2.52 approx equal to 2.5
Cl: 1.25 / 1.25 = 1
However, we cannot have fractions in the formula, so multiply everything by 2:
C: 3.5*2 = 7
H: 2.5*2 = 5
Cl: 1*2 = 2
So the empirical formula is C7H5Cl2
The molar mass of the empirical formula is 160
But the formula mass is 320
So the number of units of the empirical formula in the molecular formula is (320/160) = 2
So your molecular formula is (C7H5Cl2)2 = C14H10Cl4
I hope it's right.