# Chemistry empirical FORMULA HELPWatch

#1
Determine the empirical formula of a compound with the following composition by mass: 60.0 % C,
8.0 % H and 32.0 % O. [C5H8O2] If 100 mg of this compound is neutralized with exactly 10.0 mL of
0.0500 M NaOH in a reaction with a 1:1 stoichiometry, what is the molecular formula of
this compound?
[C10H16O4]

I understand how to work out empirical formula but not the second part of q
0

8 months ago
#2
For the second part you have to find out what the Mr of the substance is. To do that you find the Moles of NaOH and since its a 1:1 ratio the moles for NaOH will be the same as the substance. Then to get the Mr you do 100 divide by 1000 to turn mg to g and then divide that by the number of moles you got. From there you can figure out what the molecular mass is comparing the Mr you calculated and the Relative molecular mass of the empirical formula. For example if the mr you calculated was 150 and the mr of the empirical formula was 50 you would need to multiply the empirical formula by 3 to get the molecular formula
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• Sheffield Hallam University
Wed, 17 Jul '19
• Regent's University London
Wed, 17 Jul '19
• Norwich University of the Arts
Thu, 18 Jul '19

### Poll

Join the discussion

#### Are you tempted to change your firm university choice now or on A-level results day?

Yes, I'll try and go to a uni higher up the league tables (125)
19.69%
Yes, there is a uni that I prefer and I'll fit in better (59)
9.29%
No I am happy with my course choice (358)
56.38%
I'm using Clearing when I have my exam results (93)
14.65%