ap chemistry

Consider the following unbalanced reaction.
P4(s) + F2(g) PF3(g)
How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield?

I did 212/.798=265.66 grams
do I convert that to moles next?

asked by Kris
  1. Yes.

    posted by DrBob222
  2. i got 88 mol. is that right?

    posted by Kris
  3. No. mols = grams/molar mass

    posted by DrBob222
  4. 265.66g x (1mol/88) = 3.01 mol PF3

    correct?

    posted by Kris
  5. very good. Now convert mols PF3 to mols F2 BUT make sure the equation is balanced first. I didn't check it--it may be balanced now.

    posted by DrBob222
  6. the balanced equation is P4+6F2-->4PF3

    so i have:
    3.01mol PF3 x (6 molF2/4molPF3)=4.5mol2F2

    So then i convert it to grams, correct?

    posted by Kris
  7. Yes, almost.
    I would have rounded the 265.66/88 = 3.0189 to 3.02, then 3.02 x 6/4 = 4.528 which I would round to 4.53 mols F2 and convert that to grams. Actually, I never round step by step. I leave those numbers in my calculator and use the answer to one as the first number in the next step. Something like this.
    212/88 = ?
    ? x 6/4 = ?
    ? x molar mass F2 = ? grams, then round that to three significant figures since the 212 had three in the problem.

    posted by DrBob222
  8. so is the answer 171 g F2?

    I did:
    4.5 mol F2 x (38 g/1mol) =171g

    posted by Kris
  9. Thank you very much!

    posted by Kris
  10. Almost. If you use the rest of the 4.5 (4.528) x 38 I get 172 g. Also, I see in my last response that I omitted a step but I think you have the process down ok.

    posted by DrBob222
  11. How would you find the remaining mass of the excess reagent?

    posted by Brian

Respond to this Question

First Name

Your Answer

Similar Questions

  1. chemistry

    Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield?
  2. Chemistry

    Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) What mass of F2 is needed to produce 212 g of PF3 if the reaction has a 84.2% yield?
  3. chemistry

    Consider the following unbalanced reaction. P4(s) + 6F2(g) 4PF3(g) How many grams of F2 are needed to produce 114. g of PF3 if the reaction has a 78.1% yield? i tried it and got this 114g PF3 x (mol PF3/87.97g PF3) x (6 mol F2/
  4. Chemistry

    Consider the following unbalanced reaction. P4(s) + F2(g)---> PF3(g) How many grams of F2 are needed to produce 114 g of PF3 if the reaction has a 80.3% yield? I've worked it every way I can think, and the online grader says I
  5. ap chem

    P4 + F2 = PF3 What mass of F2 is needed to produce 120 gm of PF3, if the reaction has 81.1 % yield?
  6. chemistry

    In the reaction below, ΔH°f is zero for ___________. Ni(s) + 2CO(g) + 2PF3(g) = Ni(CO)2(PF3)2(l) Ni(s) CO(g) Ni(CO)2(PF3)2(l) both CO(g) and PF3(g) PF3(g)
  7. chemistry

    What mass of F2 is needed to produce 116 g of PF3 if the reaction has a 77.4% yield?
  8. chemistry 1

    if 20.2g of zn react with and equal amount of magnesium chloride to form magnesium and zinc chloride[zn+mgcl2> mg+zncl2] a.what is the limiting reactant? b. how much magnesium will be produced? Here is the way to solve most of
  9. Chemistry 130

    Will someone help me by letting me know if I did these correct, or if there the correct answers? Thanks! 2 (10). If two moles of hydrogen gas (H2) react in the following equation, how many moles of H2O will be formed? 2H2 + O2
  10. Chemistry (Check)

    PF3 reacts with XeF4 to give PF5 2PF3(g) + XeF4(s) --> 2PF5(g) + Xe(g) How many moles of PF5 can be produced from 100.0 grams of PF3 and 50.0 grams of XeF4? 100.0gPF3 x (1molePF3 / 87.96896gPF3) x (2molesPF5 / 2molesPF3) =

More Similar Questions