Sig figs


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Sig figs

Postby Steven_Liu_3H » Fri Feb 03, 2017 7:40 pm

How do we deal with sig figs when using ln(T2/T1)?

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Re: Sig figs

Postby Chem_Mod » Fri Feb 03, 2017 11:06 pm

For logs and natural logs, usual convention is this:
If the ratio of T2/T1 has x number of sig figs, then the answer to a log or natural log should have x decimal places.

Example: If I had ln(0.5/2.0), the answer to 0.5/2.0 has 1 sig fig thanks to the 0.5. So, when you solve for the natural log, your answer should have 1 decimal place. The proper answer to ln (0.5/2.0) is -1.4.

I hope this helps.

Annie Zhang_ 3C
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Re: Sig figs

Postby Annie Zhang_ 3C » Sat Feb 04, 2017 1:46 pm

To add to the above, the textbook (6th edition) has notes for how to do sig figs on pages A5 and F10 of the appendix. Specifically, rules for logarithms and exponentials are on page A6 that basically say that the answer should have the same number of sig figs as the original number. Hope that looking for more background explanation in the textbook will also be of help to you!

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Re: Sig figs

Postby Camille_2G » Sun Mar 19, 2017 10:40 am

What about sig figs for exponents? Like if you had e^3.18, would you have two total sig figs in your answer or would you have two decimal places in your answer?

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