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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: danimalswim on November 26, 2013, 12:30:37 AM

Title: Significant digits
Post by: danimalswim on November 26, 2013, 12:30:37 AM

Fe2(CO3)3=Fe2O3+3CO2
If I have 5.00 grams of iron (III) carbonate, how many mL of CO2 will I produce?
5.00 grams is .017 mol of Fe2(CO3)3, which converts to .051 mol of CO2=1143 mL.
Why is it not 1140 mL?
Did I get all of my significant digits correct?
Thank you! :)

Title: Re: Significant digits
Post by: Borek on November 26, 2013, 03:36:46 AM

1143 to 3 significant digits is 1.14×10³ (or 1140).

Note that 5.00g of Fe₂(CO₃)₃ is 0.0171 moles (3 significant digits), not 0.017 (2 SD).