midterm question

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Edward Suarez 1I
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Joined: Fri Sep 28, 2018 12:27 am

midterm question

Postby Edward Suarez 1I » Wed Dec 05, 2018 3:40 am

so Q2 from the midterm stated that "A chemist wanting to determine the molecular formula of gallic acid burned 1.000 g of the compound in an elemental analyzer. The products of the combustion were 1.811 g of CO2 and 0.3172 g of H2O. "

how can the products be more than the weight of the reactants?

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Joined: Mon Oct 01, 2018 12:16 am

Re: midterm question

Postby 905109118 » Wed Dec 05, 2018 7:53 am

Well you're not really looking to balance the reaction on this problem. Its more of finding out how many atoms of each molecule (H, C, O) you have.

Becky Belisle 1A
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Joined: Fri Sep 28, 2018 12:18 am

Re: midterm question

Postby Becky Belisle 1A » Wed Dec 05, 2018 9:04 am

The other reactant is oxygen. So the mass of the oxygen contributes to the mass of the products.

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Joined: Fri Sep 28, 2018 12:18 am

Re: midterm question

Postby 705192887 » Wed Dec 05, 2018 9:26 am

The third "hidden" reactant is oxygen. It is in excess so its original mass is not given. Therefore, this excess oxygen can account for the discrepancy in mass between the products and reactants.

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