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Title: help. due tomorrow and Im stuck on the last few. Post by: poshmom on Nov 14, 2011 1- A 15.0 g sample of water reacts with PCl3 according to the following equation:
3H2O(l) +PCl3(g)>H3PO3+3HCl(aq) How many g of H3PO3 are produced? 2- A 25.0g sample of Fe3O4 reacts with O2 to produce Fe2O3: 4Fe2O4(s) + O2(g)>6Fe2O3(s) Determine the number of g of Fe2O3 produced? 3-If you performed the experiment in #2 and actually obtained 20.3g of Fe2O3, what is the % yield? Title: Re: help. due tomorrow and Im stuck on the last few. Post by: duddy on Nov 14, 2011 2- A 25.0g sample of Fe3O4 reacts with O2 to produce Fe2O3: 4Fe2O4(s) + O2(g)>6Fe2O3(s) Determine the number of g of Fe2O3 produced? moles Fe3O4 = 25.0g /231.54 g/mol = 0.1079 the ratio between Fe3O4 and Fe2O3 is 4 : 6 moles Fe2O3 = (0.1079 x 6) / 4 = 0.1619590567504535 mass Fe2O3 = 0.1619590567504535 mol x 159.69 g/mol = 25.86324177247992 g 3-If you performed the experiment in #2 and actually obtained 20.3g of Fe2O3, what is the % yield? Use: percent yield = (actual yield / theoretical yield) x 100 Theoretical Yield and Percent Yield from Thinkwell Chemistry (http://www.youtube.com/watch?v=1L12_TRSql8&feature=player_embedded#) Title: Re: help. due tomorrow and Im stuck on the last few. Post by: poshmom on Nov 14, 2011 Thanks for the video clip. I am having a hard time finding out how you figure our moles/g...
Title: Re: help. due tomorrow and Im stuck on the last few. Post by: duddy on Nov 14, 2011 1- A 15.0 g sample of water reacts with PCl3 according to the following equation: 3H2O(l) +PCl3(g) --> H3PO3+3HCl(aq) How many g of H3PO3 are produced? Use molar mass to find moles: 15.0 grams of H2O @ 18.01 g/mol = 0.832870627429206 moles of H2O By the equation PCl3 + 3H2O --> H3PO3 + 3HCl 0.832870627429206 moles of H2O produces 1/3 as many moles of H3PO3 = 0.277623542476402 moles H3PO3 using molar mass 0.277623542476402 moles H3PO3 @ 82.00 g/mol = your answer 22.76513048306496 grams of H3PO3 |