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How to express answers

Posted: Wed Oct 09, 2019 12:45 am
by EricZhao3G
I just switched into this class and was wondering if Dr. Lavelle ever mentioned how he wanted answers formatted. Are we supposed to use scientific notation or SI prefixes or does it not matter?

Re: How to express answers

Posted: Wed Oct 09, 2019 8:19 am
by claribel charway 1I
He hasn't said how he wants them expressed. I would go with scientific notation with the base units (g, mole, L). Just always make sure your sig figs are correct.

Re: How to express answers

Posted: Wed Oct 09, 2019 9:10 am
by Emily Mendez 4C
He hasn't really specified if he wants a certain format, but he has told us to know about sig figs and scientific notation.

Re: How to express answers

Posted: Wed Oct 09, 2019 10:34 am
by Lauren Tanaka 1A
I went to one of the UA sessions and they said we should mostly use scientific notation for our answers. That being said you also have to be aware of sig figs when you express an answer in scientific notation.

Re: How to express answers

Posted: Thu Oct 10, 2019 10:34 pm
by KayleyW_3L
I'm still a little confused as to when I should use scientific notation or not. For example, the textbook solution for Fundamentals E.23 part a is 0.0134 mol Cu^2+, while the solution for E.23 part b is 8.74x10^-3.

Why did they decide not to use scientific notation for part a?

Re: How to express answers

Posted: Fri Oct 11, 2019 12:23 am
by Brianna Becerra 1B
While he has not explicitly stated, scientific notation pops up a lot as well as the role and importance of sig figs.

Re: How to express answers

Posted: Fri Oct 11, 2019 9:08 am
by Justin Quan 4I
KayleyW_3L wrote:I'm still a little confused as to when I should use scientific notation or not. For example, the textbook solution for Fundamentals E.23 part a is 0.0134 mol Cu^2+, while the solution for E.23 part b is 8.74x10^-3.

Why did they decide not to use scientific notation for part a?


Using scientific notation is just a matter of convenience, for example for part a, it may be easier to write the answer normally, whereas part b has more decimal places so its probably easier to use scientific notation. Normally, you choose to use scientific notation to better show the number of sig figs you have in your final answer.

Re: How to express answers

Posted: Fri Oct 11, 2019 12:39 pm
by ValerieChavarin 4F
KayleyW_3L wrote:I'm still a little confused as to when I should use scientific notation or not. For example, the textbook solution for Fundamentals E.23 part a is 0.0134 mol Cu^2+, while the solution for E.23 part b is 8.74x10^-3.

Why did they decide not to use scientific notation for part a?

I've noticed that scientific notation is often recommended when there is a change in at least 3 decimal places, such as 10^-3.

Re: How to express answers

Posted: Fri Oct 11, 2019 12:47 pm
by Charisse Vu 1H
I don't believe that sig figs are too important in this class. My TA told us that sig figs are not too big of a deal, as long as you do not round to whole numbers or to only 1 decimal place when the answer should clearly have 2 or 3 decimal places. As for scientific notation, I believe that it is more of a convenience, although it never hurts to use scientific notation!

Re: How to express answers

Posted: Fri Oct 11, 2019 12:59 pm
by Nikki Razal 1L
^^ agreed, my TA told me not to be worried about sig figs at all, but I'd just be aware of it. also, I heard when writing out chemical equations, just write the states of each element to be safe (ie. (aq),(l),(g),(s))

Re: How to express answers

Posted: Sun Oct 13, 2019 6:41 pm
by Areena H 2K
Dr. Lavelle hasn't mentioned if he prefers them in scientific notation or not, however I assume he wants us to know how to use it but questions don't specifically ask to format it into scientific notation so I don't we have to, it is just preferred. As for, sig figs my ta said on the exams they won't take points off for not having it however it would be best to know how to put the answer in the correct formatting for the amount of sig figs.

Re: How to express answers

Posted: Sun Oct 13, 2019 11:00 pm
by KayleyW_3L
Thank you, I see! So I should could technically use scientific notation for 0.0134, but it is generally not as often used for when the power of ten is (negative) 3 or more.

Re: How to express answers

Posted: Sat Oct 19, 2019 12:16 pm
by serenabirkhoff_1K
Charisse Vu 3E wrote:I don't believe that sig figs are too important in this class. My TA told us that sig figs are not too big of a deal, as long as you do not round to whole numbers or to only 1 decimal place when the answer should clearly have 2 or 3 decimal places. As for scientific notation, I believe that it is more of a convenience, although it never hurts to use scientific notation!


If you did have to use sig figs how would you know how many to have in the answer?

Re: How to express answers

Posted: Sat Oct 19, 2019 12:29 pm
by Amanda Mei 1B
serenabirkhoff_1K wrote:
Charisse Vu 3E wrote:I don't believe that sig figs are too important in this class. My TA told us that sig figs are not too big of a deal, as long as you do not round to whole numbers or to only 1 decimal place when the answer should clearly have 2 or 3 decimal places. As for scientific notation, I believe that it is more of a convenience, although it never hurts to use scientific notation!


If you did have to use sig figs how would you know how many to have in the answer?


You would use the same number of sig figs as the information provided in the problem. For example, if you started with a sample of 253 grams of something and were asked to calculate something based off of that, your answer would also be expressed in 3 sig figs.