### Rounding

Posted:

**Sun Nov 03, 2019 8:48 pm**When is it appropriate to round when finding the empirical formula? For example, is alright to round up from 1.6 or 1.8 to 2, or should we multiply by another number to find a whole number?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=11&t=50158

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Posted: **Sun Nov 03, 2019 8:48 pm**

When is it appropriate to round when finding the empirical formula? For example, is alright to round up from 1.6 or 1.8 to 2, or should we multiply by another number to find a whole number?

Posted: **Sun Nov 03, 2019 8:54 pm**

Typically, we are looking for multiples of 2 (#.5), 3 (#.33, #.66), or 4 (#.25, #.75) so we can determine whether or not it is necessary to multiply up. For the purposes of this class, it won't be anything ambiguous.

Posted: **Sun Nov 03, 2019 8:55 pm**

You should only round to a whole number when the decimal is extremely close to a whole number. For example, 1.96 to 1.99 can be rounded to 2. However, 1.6 or 1.8 should be multiplied to a whole number.

Posted: **Sun Nov 03, 2019 8:55 pm**

I believe .9 and above is a safe range for rounding up. Anything lower I would multiply to get the numbers behind the decimal point to 0.9 or higher. Hope this helps.

Posted: **Sun Nov 03, 2019 9:06 pm**

I usually just see if multiplying by a number will clearly make it even. i.e if it is 1.66, even though that is close-is to 2, it is easy to see that multiplying by 3 will get us much closer to a whole number. if the number is like 1.97 though it's definitely safe to round up!

Posted: **Sat Dec 07, 2019 9:14 pm**

I would only round up if the value is very close to a whole number and the other values are already established as whole numbers

Posted: **Sat Dec 07, 2019 11:45 pm**

I would only round if it was very close to a whole number. I think anything above 0.9 is safe, but anything less should be multiplied to get whole numbers across the board.