Empirical Formula - Whole Number Ratio

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Stacey Phan 2I
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Empirical Formula - Whole Number Ratio

Postby Stacey Phan 2I » Wed Oct 28, 2020 1:21 pm

I was wondering what the cutoff for rounding the moles to a whole number is. I am assuming if its less than .10 away you can round it to the nearest number?

Madilyn Schindler 3E
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Re: Empirical Formula - Whole Number Ratio

Postby Madilyn Schindler 3E » Wed Oct 28, 2020 1:26 pm

I don't think there is a literal cutoff for rounding. In most cases, it should be fairly obvious whether or not the number should be rounded up or not, as the numbers are usually less than 0.2 away from a whole number. Just go with your gut and you'll be fine.

Ashlen Bullock 1H
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Re: Empirical Formula - Whole Number Ratio

Postby Ashlen Bullock 1H » Wed Oct 28, 2020 1:28 pm

I do not think there is a set value. Usually round to the nearest whole number if it is like less than .10 away. If it is more, then try multiplying it by integers until you get a whole number.

SelenaDahabreh1D
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Re: Empirical Formula - Whole Number Ratio

Postby SelenaDahabreh1D » Wed Oct 28, 2020 2:14 pm

There isn't really a set-in-stone cut off value for rounding moles to a whole number. But, in some of the UA sessions I've attended, they said to just use your logic in rounding and typically round down or up is the value is less than 0.1 or greater than 0.9. Hope this helps!

EnricoArambulo3H
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Re: Empirical Formula - Whole Number Ratio

Postby EnricoArambulo3H » Wed Oct 28, 2020 2:15 pm

I don't think that there is a set value to round to the nearest whole number. However if you see that it is a rather large difference (like 4/3 or 3/2), then I would try multiplying the ratios until you get a whole number for each atom. Hope this helped!

Shalyn Kelly 3H
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Re: Empirical Formula - Whole Number Ratio

Postby Shalyn Kelly 3H » Wed Oct 28, 2020 2:27 pm

Hi! Agreeing with everyone above, just go with your gut feeling for rounding. If you have to multiply by an extremely large number for it to work out or you feel like something is off, you can always check your previous calculations as well to be sure nothing went wrong there. Generally, I aim for less than .20 away from the whole number before rounding.

Kimiya Aframian IB
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Re: Empirical Formula - Whole Number Ratio

Postby Kimiya Aframian IB » Wed Oct 28, 2020 2:30 pm

Stacey Phan 3I wrote:I was wondering what the cutoff for rounding the moles to a whole number is. I am assuming if its less than .10 away you can round it to the nearest number?

Hi! I would say in general if it is near about .1 then it is ok to consider that it is a whole number. I think that in our class it will be obvious if we need to multiply by another number. By that I mean that we would probably get something like 1.333 (multiply by three) or 2.5 (multiply by 2) where it would be clear. Hope this helps!

Jasraj Parmar 3H
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Re: Empirical Formula - Whole Number Ratio

Postby Jasraj Parmar 3H » Wed Oct 28, 2020 2:41 pm

No, there isn't really a specific cutoff for empirical formulas. I think in most cases if you do the steps right you should be able to get a pretty good ratio. I wouldn't worry too much about it.

Helena Hu 3E
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Re: Empirical Formula - Whole Number Ratio

Postby Helena Hu 3E » Wed Oct 28, 2020 9:23 pm

I think with the questions that we're asked in this course, the rounding should be pretty clear if all the steps were right. With the practice we've had so far with the Sapling hw and the textbook questions, most of the decimals came out to be values like .98 or .002 (things that make it clear where the rounding should be).

Michelle Nguyen 3F
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Re: Empirical Formula - Whole Number Ratio

Postby Michelle Nguyen 3F » Sat Nov 07, 2020 11:50 pm

I do not think that there is a cutoff for rounding, especially since the numbers just tend to be very close to round. There would be "cutoffs" for when we should round, such as having _.33 and then multiplying by 3 to get the closest number.


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