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Prelab for Experiment 10- Analysis of Phosphorus in Plant Food ail answers except for question 2 should be reported to at least 3 significont figures Phosphoric acid, H3PO4, has some important applications. It can be used to produce fertilizers and it is present in soft drinks. Phosphoric acid can be made from phosphorus in a two step process: Reaction 1: P4+502-P4O10 Reaciion 2: P40o+6H20+4H3PO4 1. What is the molar mass of phosphoric acid, HaPO4? Report your answer to 3 significant figures. g/mol How many moles of H3PO4 can be produced from one mole of P4? Hint: You need to look at both reaction (1) and reaction (2). Your answer should be a simple whole number 2. mol 3. A synthesis yielded 174 g of H3PO4. How many moles of HsPO4 were produced? mol 4. How many moies of P4 wouici be required to produce the number of moies of H3PO4 determined in question 3? mol Convert the moles of P4determined in question 4 into grams. This will tell us the 5. grams of P4 that actuaiily reacted. Hint: Here you need to use the molar mass of P4,not the molar mass of P. 6. Let's say that the experimentalist actually used 175 g from a bottle labeled P4. Based on your answer to question 5, you can see that it did not all react. We will assume that this was because the reagent in this bottle contained inert impurities. Based upon your answer to question 5 and the mass of the reagent taken from the bottle labeled P4,what was the actual mass percent of P4 in the bottle? Hint: Be sure to convert Into a percentage (by multiplying the fraction by 100%). %w/w Submit Question

Answer 1

1. The malan mass dH3 PO4 Can be caleula ted as below x1)+31 +4x19/ 11 9/mo1 98 / m 01 three significt 98.6 adding the two neaction we see that Cam + Pa 010 t620 Po10 4 H3PO PA +502 P 502 t6 H20 4 t3P04 Thus fnom 1 mol Pa we get mol mot 4 Aus

Nomdes H3 PO4 mass Ha P04 in H3P04 /mo molar mass 17 4 thra ee significant igit mdes f H3 P04 were mol Theis the no pnoduced Aus (in 2) 4. we have seen that to Abovea 4 mol H PO4 we need 1 mol Thus to bnoa uce 177 mo 1-77 will need we Pa mol 4 0.44 2 mol PA Sothe answer is 0.44 2 mol Aur

molan mass P4 (4 x31) 3/m0 2 4 9/mo Thus 0-44 2 mo =0-44 2 m X 124 9/ms 9Pa Phree significant figwres 54.8 So the answeris 54. 8 3 Au bercent of Pa mars actually us ed x to mars mass taken from bottle 54 8 31-3 So the con nect ansder 31. 2 Aut 11