# Chemistry : molecular formula

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#1
I’m given the percentages of the elements and given a range from 70-100 for the Mr , what steps should I use to determine the molecular formula
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10 months ago
#2
(Original post by Heixi)
I’m given the percentages of the elements and given a range from 70-100 for the Mr , what steps should I use to determine the molecular formula
First of all whats the actual question so then i can help u understand the steps
0
#3
Analysis shows a compound to have 36.364 % oxygen , 54.545% carbon.the remainder is hydrogen . If the compound is known to have a molecular mass in the range 70-100. Determine the molecular formula of the compound
0
10 months ago
#4
(Original post by Heixi)
Analysis shows a compound to have 36.364 % oxygen , 54.545% carbon.the remainder is hydrogen . If the compound is known to have a molecular mass in the range 70-100. Determine the molecular formula of the compound
Ohhhh ok so first work out empirical formula by doing molar ratio eg 36.54/16 etc.
The put in whole number ratio ie CH3O
Then use this to calculate the molecular formula which would be within the range.

According to forum i cant acc give u exact working out, so thats kinda the general method. Pm if youre still stuck
0
#5
(Original post by tbi_zlx)
Ohhhh ok so first work out empirical formula by doing molar ratio eg 36.54/16 etc.
The put in whole number ratio ie CH3O
Then use this to calculate the molecular formula which would be within the range.

According to forum i cant acc give u exact working out, so thats kinda the general method. Pm if youre still stuck
So i would do trial and error till i get something in the range?
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