This is a limiting reagent (LR) problem.
2NH4F + Ca(NO3)2 ==> CaF2 + 2NH4NO3
1. Write and balance the equation as above.
2. Convert numbers to mols. mols = M x L = ?
mols Ca(NO3)2 = M x L = ?
mols NH4F = M x L = ?
3a. Using the coefficients in the balanced equation, convert mols Ca9NO3)2 to mols CaF2.
3b. Do the same to convert mols NH4F to mols CaF2.
3c. It is likely that the two values for 3a and 3b will not agree which means one of them is not right. The correct value in LR problems is ALWAYS the smaller value.
4. Using the smaller value for mols CaF2 convert to grams. g = mols x molar mass. This is the theoretical yield (TY)
The actual yield (AY) is 1.524 in the problem.
5. %yield = (AY/TY)*100 = ?
A solution of calcium nitrate, Ca(NO3)2, reacts with a solution of ammonium fluoride, NH4F, to form solid calcium fluoride, CaF2, and ammonium nitrate, NH4NO3(aq). When 45.00 mL of 4.8724 x 10-1 M Ca(NO3)2 solution was added to 60.00 mL of 9.9981 x 10-1 M NH4F solution, 1.524 g of CaF2 was isolated.
Calculate the percent yield of CaF2
1 answer
1 answer