## Empirical Formula [ENDORSED]

NatBrown1I
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

### Empirical Formula

What is the empirical formula when mass is not equal to 100?

uhedlund
Posts: 38
Joined: Wed Nov 15, 2017 3:03 am

### Re: Empirical Formula  [ENDORSED]

Using percentages, you can calculate as though the sample were 100 g. Example: 60% O, 30% H, 10% N. Use 60 g O, 30 g H, and 10 g N.

904914037
Posts: 65
Joined: Wed Sep 18, 2019 12:16 am

### Re: Empirical Formula

Yes, I believe professor also said that it doesn't have to be 100g. That number is chosen to make the process of calculating the empirical formula easier. It would still work if you assumed a sample mass of 50g, you would just have masses that are half as large as if you assumed a sample mass of 100g. It is just a way of turning the percentages into a mass value.

Alex Tchekanov Dis 2k
Posts: 118
Joined: Sat Aug 24, 2019 12:16 am

### Re: Empirical Formula

I agree with both other answers above, but the way I think about the 100g concept is that rather than the actual mass being 100g, it is a comparison. Because of the mass percentage of an element in a given molecule will be the same whether you have 10g of the molecule or 1000g. Thus, we use an easy number to calculate with,100, to find the mass percentage.

Anisha Chandra 1K
Posts: 118
Joined: Thu Jul 11, 2019 12:17 am

### Re: Empirical Formula

I agree with the other answers, and something else to note is you can do the problem without percentage if you just convert each element to moles and divide each element's number of moles by the smallest number of moles out of the elements you are dealing with.

Arianna Perea 3H
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

### Re: Empirical Formula

When writing the empirical formula, does it matter which element in the compound goes first?

Lindsey Chheng 1E
Posts: 110
Joined: Fri Aug 30, 2019 12:16 am

### Re: Empirical Formula

Typically, compounds are written as the cation first then the anion, or metals first then nonmetals (Hydrogen is an exception).