Significant Figures

Moderators: Chem_Mod, Chem_Admin

michelleguan3a
Posts: 14
Joined: Fri Sep 26, 2014 2:02 pm

Significant Figures

Postby michelleguan3a » Mon Dec 01, 2014 1:08 am

I am a bit confused about when we round for significant figures. In the solution manual, the values are rounded to the correct number of significant figures in each step. Are we supposed to do this or do we round to the correct number of significant figures at the very end of the calculation?

Patrick Chin 1F
Posts: 45
Joined: Fri Sep 26, 2014 2:02 pm

Re: Significant Figures

Postby Patrick Chin 1F » Mon Dec 01, 2014 12:34 pm

You only have to have the correct number of sigfigs for the last answer that you box. For the steps you take to get to the answer, you do not need to have correct sigfigs. However, be careful that you don't truncate numbers in each step, or else the answer you get will not be accurate, even if you have the right number of sigfigs. Just to be safe, it's better to follow sigfigs in your steps too.

michelleguan3a
Posts: 14
Joined: Fri Sep 26, 2014 2:02 pm

Re: Significant Figures

Postby michelleguan3a » Mon Dec 01, 2014 1:35 pm

So is it better to do the correct number of significant figures during each step or to use more than the correct number of significant figures to make the answer more accurate? These two methods gives different answers. The solution manual seems to truncate the values during each step and uses the correct number of sig figs. However, the answer is not as accurate. What should we do on the quiz?

Sophie Sha 1A
Posts: 10
Joined: Fri Sep 26, 2014 2:02 pm

Re: Significant Figures

Postby Sophie Sha 1A » Mon Dec 01, 2014 7:57 pm

I'm pretty sure we use exact values during the calculations and round to the correct number of significant figures at the end. I remember Professor Lavelle or my TA saying this.

HelenMach 1J
Posts: 12
Joined: Fri Sep 26, 2014 2:02 pm

Re: Significant Figures

Postby HelenMach 1J » Tue Dec 02, 2014 4:30 pm

Agreed with Sophie. Remember my T.A. advising us to take a few places over the sig fig amount and just do sig fig at the end. This will give the most accurate answer available.


Return to “Equilibrium Constants & Calculating Concentrations”

Who is online

Users browsing this forum: No registered users and 3 guests