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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Shack05 on November 10, 2010, 07:51:09 pm

Title: Sig figs.
Post by: Shack05 on November 10, 2010, 07:51:09 pm

Looking at q2.c.ii of 2009 paper
the examiner's report gives it to 2 s.f (9.1x10^-6)
I thought it should have been to three, does the fact that it is log to the base 10 mean it is 2 sig figs lol?

Title: Re: Sig figs.
Post by: jasoN- on November 10, 2010, 07:52:19 pm

Yes my thoughts too.
It should be 3 sig figs, unless they ridiculously used the sig figs on the enthalpy value of part (a) (completely irrelevant)

Title: Re: Sig figs.
Post by: crayolé on November 10, 2010, 10:10:45 pm

Is any calculation involving combustion of alkanes/alkanols 2 sig figs because of the hydrogen in the molar mass?

Title: Re: Sig figs.
Post by: Edmund on November 10, 2010, 10:50:35 pm

Quote from: Shack05 on November 10, 2010, 07:51:09 pm

Looking at q2.c.ii of 2009 paper
the examiner's report gives it to 2 s.f (9.1x10^-6)
I thought it should have been to three, does the fact that it is log to the base 10 mean it is 2 sig figs lol?

Yeah you should round it off to 3 sig figs.

Quote from: crayola on November 10, 2010, 10:10:45 pm

Is any calculation involving combustion of alkanes/alkanols 2 sig figs because of the hydrogen in the molar mass?

Not really, you need to round off your answer to the least sig figs according to data given.