yulmart Posted November 18, 2015 Report Share Posted November 18, 2015 I'm doing a lab and I'm a bit confused by the significant digits in the final processed data. For example, suppose I was determining the heat lost by a system and the data in the first trial was:​m: 0.500 kgc: any constant, let's say 0.800temp. initial: 25.0temp. final: 21.0​​​​Q = (0.500) * (0.800) * (25.0-21.0)Q = (0.500) * (0.800) * (4.0)Q = 1.6​​My final answer has 2 significant figures according to the calculation shown above but, my raw data all had 3 significant figures. I've heard people say that keep the same amount of significant figures as the raw data. So what would I do in this case?​ Reply Link to post Share on other sites More sharing options...
kw0573 Posted November 18, 2015 Report Share Posted November 18, 2015 You keep # of significant figures for multiplication/division, and place value (typically decimal places) of least significant number for addition/subtraction.Here when you multiply, the change in temperature is in fact only goes to the tenths digit, or 2 sig figs, so your calculations are correct. 1 Reply Link to post Share on other sites More sharing options...
Msj Chem Posted November 18, 2015 Report Share Posted November 18, 2015 (edited) I would keep the final answer as 3 SF.The number of SF in your final answer depends on the precision of your apparatus. Leave your calculations as this:Q = (0.500) * (0.800) * (25.0-21.0)Then you can give your final answer to 3 SF. Edited November 18, 2015 by Msj Chem Reply Link to post Share on other sites More sharing options...
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