Significant Figures In A Given Weight

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Ethan Goode 2H
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Significant Figures In A Given Weight

Postby Ethan Goode 2H » Sun Oct 04, 2020 4:59 pm

If it is given that there are 7 grams of a substance in a mole of that, would you use the one significant figure in the given value to formulate how many significant figure the final answer would be after calculation?

Faaizah Arshad 1H
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Re: Significant Figures In A Given Weight

Postby Faaizah Arshad 1H » Sun Oct 04, 2020 5:20 pm

I believe that since 7 is an integer, it should not affect the significant figures in your calculation. Integers and exact numbers do not affect sf. You would most likely be given an inexact measurement that could be used as the least number of significant figure to determine your answer.

Take a look at the following resources for more detailed information:
https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf
https://lavelle.chem.ucla.edu/wp-conten ... ussion.pdf

Lorraine Jiang 2C
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Re: Significant Figures In A Given Weight

Postby Lorraine Jiang 2C » Mon Oct 05, 2020 2:13 am

Hi! I think if the question states "7" then it has one significant figure only. Also, numbers like 70, 700, and 7,000 all have only one significant figure because I think there is a rule that states "the last zeros of an integer number do not count as significant numbers".

Hope it helps! :)

Xinying Wang_3C
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Re: Significant Figures In A Given Weight

Postby Xinying Wang_3C » Mon Oct 05, 2020 7:52 am

Hi! I think "7" has one sig fig, and if the 7 gram is used in the calculation, it does limit the sig fig to one.

Charlotte Adams 1A
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Re: Significant Figures In A Given Weight

Postby Charlotte Adams 1A » Mon Oct 05, 2020 9:00 am

Hi! I believe you would only use one significant figure when giving your answer because when multiplying/dividing, the value with the least significant figures determines the number of significant figures in the answer and 1 sig fig is the least amount of sig figs you can have. The Everything you want to know about Significant Figures on Dr. Lavelle's website really helped!

Hope this was useful.

Shrinidhy Srinivas 3L
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Re: Significant Figures In A Given Weight

Postby Shrinidhy Srinivas 3L » Mon Oct 05, 2020 9:23 am

Make sure that you acknowledge exactly what the "7" is listed as in the problem. If it just says 7, then that's one significant figure, but if it says 7.00 that would be three significant figures. Hope this helps!

David Chibukhchian 2G
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Re: Significant Figures In A Given Weight

Postby David Chibukhchian 2G » Mon Oct 05, 2020 10:10 am

I was also confused as to whether we would consider a one-digit integer that is given in the problem to affect the number of significant figures. However, even though it's an integer, it's still not an exact, known number (I believe) and since this is the case you have to write your final answer with just one significant figure, like everyone else said. I'm still uncertain, but I think this is the reason why a value like "7 grams" would in fact affect the number of sig figs.

Cecilia Cisneros 1F
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Re: Significant Figures In A Given Weight

Postby Cecilia Cisneros 1F » Mon Oct 05, 2020 10:13 am

In this case, if it is given as "7" then you should use only one significant figure in your answer! In the case of "7.0", 2 sig figs, or "7.00", 3 sig figs, then there would be 2 sig figs or 3 sig figs in your answer. As long as you use as many sig figs as there were given in the problem, then your answer would just contain the same amount of sig figs.

Jay Solanki 3A
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Re: Significant Figures In A Given Weight

Postby Jay Solanki 3A » Mon Oct 05, 2020 10:20 am

For that question I believe that since 7 is an integer, there is no specific amount of significant figures that you should use. I would suggest using only 1 anyway since there are no zeros after the integer, just to be safe. Usually for questions involving moles and grams, you should use the least number of significant figures that are given in the question. For instance, if the question gives you 1.7 g and 0.115 M (or something otherwise), use only 2 significant figures since 1.7 only has 2. Hope this helps!

Inderpal Singh 2L
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Re: Significant Figures In A Given Weight

Postby Inderpal Singh 2L » Mon Oct 05, 2020 10:22 am

For anyone having trouble with significant figures, the following link is what I use if I ever get confused.

https://getstartedinscience.weebly.com/ ... orig.jpg?1

This summarizes the rules of significant figures pretty well :)

Kaiya_PT_1H
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Re: Significant Figures In A Given Weight

Postby Kaiya_PT_1H » Thu Oct 08, 2020 12:19 pm

Jay Solanki 3E wrote:For that question I believe that since 7 is an integer, there is no specific amount of significant figures that you should use. I would suggest using only 1 anyway since there are no zeros after the integer, just to be safe. Usually for questions involving moles and grams, you should use the least number of significant figures that are given in the question. For instance, if the question gives you 1.7 g and 0.115 M (or something otherwise), use only 2 significant figures since 1.7 only has 2. Hope this helps!


So if any number is an integer, it doesn't count for significant figures? I thought the difference was whether it was a measurement or a given value. In this case, since it's 7 grams (a measurement specific to the problem), wouldn't it just be 1 significant figure as Cecilia said?

TrishaP_3E
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Re: Significant Figures In A Given Weight

Postby TrishaP_3E » Thu Oct 08, 2020 12:25 pm

I read that "exact numbers, such as integers, are treated as if they have an infinite number of significant figures," and so you dont need to look at integers for determining sig figs.

Heres the link I used:http://www.chemistry.wustl.edu/~coursedev/Online%20tutorials/SigFigs.htm#:~:text=Rules%20for%20Using%20Significant%20Figures&text=Exact%20numbers%2C%20such%20as%20integers,if%20it%20is%20below%205.


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