What is the empirical formula according to this data?
Element: Weight in 10 g of sample
C 5.214
H 1.313
O 3.473
I got C2H5O. Is this correct?
2007-04-06 15:11:09 · 4 answers · asked by Alan l 1 in Science & Mathematics ➔ Chemistry
C=52.14/12.011=4.34 mole C
H=13.13/1.0079= 13.02 mole H
O=34.73/15.9994=2.17 mole O
O being the least, and C is 4.34/2.17 is 2. H is 6.
Formula is 2CH6O.
VR
2007-04-06 15:57:48 · answer #1 · answered by sarayu 7 · 0⤊ 0⤋
To solve:
1. You convert grams to moles.
2. You divide each mole answer by the smallest mole answer you got from converting the grams to moles.
3. You place the answers you got into the formula as subscripts.
If you did all this, you probably got the answer right.
However, if you did step number 2 but got numbers that couldn't be rounded to the nearest whole number. For instance, 4.5 moles. Then you find a common number that will go into it. But if you got something like 4.9998 moles just round it to 5 and place it in the formula as a subscript.
2007-04-06 15:26:19 · answer #2 · answered by ? 1 · 0⤊ 0⤋
The approach is as follows:
Divide the grams of each element by its molecular mass.
This gives you the molar ratio. If it is not whole numbers, take the smallest one and divide all by this smallest one. If still not all whole numbers, repeat the process.
Once you have whole numbers, that is the empirical formula
2007-04-06 15:20:17 · answer #3 · answered by reb1240 7 · 0⤊ 0⤋
You shouldn't have. Suppose you made the weight 100 and divided by the atomic weight of each element. I would see C-4.33
H-13
O-2.16
If we set O=1, you have appx C2H6O, which is dimethyl ether as opposed to ethyl alcohol.
2007-04-06 15:30:54 · answer #4 · answered by cattbarf 7 · 0⤊ 0⤋