## Empirical Coefficients [ENDORSED]

Deap Bhandal L1 S1J
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### Empirical Coefficients

Sometimes when I solve for the empirical formula I get moles like 3.1 or 2.9. Looking at the answers, I found out that rounds to 3. After what decimal digit (3.15 or 3.2) should I multiply all the moles by a constant to get better whole numbers?

Jennie Fox 1D
Posts: 66
Joined: Sat Jul 22, 2017 3:01 am

### Re: Empirical Coefficients

Typically, you will get numbers that are very close to a whole number such as 1.97 or 3.08 which you would round to 2 and 3. In many of the problems I have done so far that I've had to multiply in order to get a whole number, I've gotten numbers like 2.67, 1.33 and 3.75 which can easily be multiplied to get a whole number (2.67 x 3, 1.33 x 3, 3.75 x 4).

Justin Chu 1G
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### Re: Empirical Coefficients  [ENDORSED]

Generally, anything that doesn't seem like it can be easily multiplied into another whole number (ex: 1.5 x 2, 2.67 x 3) can be easily rounded to its nearest integer. This usually just happens due to rounding errors with sig figs so I wouldn't worry too much. They are almost always apparent what they should round to.

504749087
Posts: 2
Joined: Fri Sep 29, 2017 7:07 am

### Re: Empirical Coefficients

Yeah that's what I learned in chemistry class, you round down when it's bellow 1.3, and round up when it's 1.8, but when its 1.5 multiply by 2, and when its 1.6 multiply by 3.

Alondra Juarez section 1E
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### Re: Empirical Coefficients

When the answer you acquire is close to a whole number such as 2.9 it is better to round up to 3 and not having to multiple by another number as it already is a whole number.

Sophia Kim 1C
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### Re: Empirical Coefficients

As far as I know, if the number is within .1 from a whole number than you would just round to that whole number. However if its more than that you would need to multiply it by a number to get it to a whole number. So if it is .25 than you would multiply by 4 or if its .5 you would multiply by 2 and etc.

Natalie LeRaybaud 1G
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Joined: Thu Jul 13, 2017 3:00 am

### Re: Empirical Coefficients

Yeah I agree. You mainly want to round when you get a number ending in like .5, .333, .666. etc. Other then that, if the number is below .5 in the tens place then round down and if above, round up.

Amy Zheng 2l
Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

### Re: Empirical Coefficients

Generally I would round to the nearest whole number if its +/- 0.1 from a whole number. Often times numbers are off a little due to rounding errors.

nanditasundarapandian1D
Posts: 21
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### Re: Empirical Coefficients

From what I learned you round up when its bigger than .5 and round down when its smaller than .5

AnuPanneerselvam1H
Posts: 52
Joined: Fri Sep 29, 2017 7:07 am

### Re: Empirical Coefficients

If the answer is .1 away from a whole number, round accordingly. If it isn't then multiply all mole ratios so they are close enough to whole numbers. For example, if one ratio is 2.25, multiply all the ratios by 4 to get whole numbers.

Yifei Wang 3G
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Joined: Fri Sep 29, 2017 7:07 am

### Re: Empirical Coefficients

nanditasundarapandian1D wrote:From what I learned you round up when its bigger than .5 and round down when its smaller than .5

but what if the last digit is exactly 5?

Elika Asis 3C
Posts: 19
Joined: Fri Sep 29, 2017 7:07 am

### Re: Empirical Coefficients

yifeiwang wrote:
nanditasundarapandian1D wrote:From what I learned you round up when its bigger than .5 and round down when its smaller than .5

but what if the last digit is exactly 5?

When we discussed rounding in my discussion section, we talked about how if it's exactly .5, you would round to the nearest even number, so if it was 3.25, you would round to 3.2, and if it was 3.35, you would round to 3.4!

Deap Bhandal L1 S1J
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Thanks guys.