Clarification on the Vitamin C Example

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Sunia Akaveka 4I
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Clarification on the Vitamin C Example

Postby Sunia Akaveka 4I » Tue Oct 01, 2019 11:53 pm

In the example given in class regarding 8.00g of Vitamin C, where the carbon amounted to 3.27g, hydrogen amounted to 0.366g, and oxygen was 4.36g, Dr. Lavelle emphasized the importance of double-checking that the sum of these amounts equal to the 8.00g. When adding these, you receive a total of 7.996g. What happens to the 0.004g that is allegedly accounted for?

andrewcj 2C
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Joined: Thu Jul 11, 2019 12:17 am

Re: Clarification on the Vitamin C Example

Postby andrewcj 2C » Wed Oct 02, 2019 12:10 am

My best guess would be that rounding caused the masses of the individual elements to be a little smaller than they really are, which creates a small discrepancy in the summed mass and the total mass. In real life, our instruments are not always perfect, and this might be trying to show that.

Ryan 1K
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Joined: Fri Aug 09, 2019 12:15 am

Re: Clarification on the Vitamin C Example

Postby Ryan 1K » Wed Oct 02, 2019 12:16 am

Elaborating on the rounding aspect, all the numbers provided have three significant figures. Since one of the numbers is less than 1, it makes sense for there to be some small mass lost in the calculations as the other numbers would be rounded.

Rishika Yadav 3D
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Re: Clarification on the Vitamin C Example

Postby Rishika Yadav 3D » Wed Oct 02, 2019 9:19 am

I think the small amount 'lost' is due to rounding - if we went out further in the decimal places then we would likely have gotten a value slightly closer to 8.000. Additionally, in real life we will nearly always be slightly off of the theoretical value, due to things like solution sticking to the beaker or other instruments, weighing issues, etc.

Sunia Akaveka 4I
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Re: Clarification on the Vitamin C Example

Postby Sunia Akaveka 4I » Wed Oct 02, 2019 6:05 pm

So, if this 0.004g is lost to discrepancy or for rounding purposes, wouldn’t this further our mass percentage composition data from accuracy? Would this be more considered precision?

Katie Bart 1I
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Re: Clarification on the Vitamin C Example

Postby Katie Bart 1I » Wed Oct 02, 2019 10:12 pm

It would, but we have to make sure we account for significant figures. Also, we lose precision every time we round so this isn't significantly worse than other problems we have done.

504939134
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

Re: Clarification on the Vitamin C Example

Postby 504939134 » Wed Oct 02, 2019 11:20 pm

I believe this was because we are supposed to round up.


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