A sloution of calcium nitrate, C(NO3), reacts with a solution of ammonium fluoride, NH4F, to form solid calcium fluoride, CaF2, and ammonium nitrate, NH4NO3(ag). When 45.00 mL of 4.8724 x 10 -1M Ca(NO3)2 solution was added to 60.00 mL of 9.9981 x 10 -1M NH4F solution, 1.524g of CaF2 was isolated.
(1) Write the equation for the reaction, showing the staes of substances.
(2) Calculate the number of moles of Ca(NO3)2 orginally present.
(3) calculate the number of moles of NH4F present
(4) Identify the limiting reagent.
(5) Calculate the theoretical yeild, in grams, of CaF2.
(6) Calculate the percent yield of CaF2.
(1) Ca(NO3)2(aq) + 2NH4F(aq) = CaF2(s) + 2NH4NO3 (aq)
(2) 2.1926 * 10^-2 mol Ca(NO3)2
(3) 5.9989 * 10^-2 mol NH4F
(4) Ca(NO3)2
(5) 1.71197 g CaF2
(6) 89.02%
Ca(NO3)2(aq) + 2NH4F(aq) ==> CaF2(s) + 2NH4NO3(aq)
2. moles = M x L
3. moles = M x L
4. Using the coefficients in the balanced equation, convert mole of Ca(NO3)2 to moles CaF2. With the same procedure, convert moles NH4F to moles CaF2. The smaller number of moles will be the correct # moles for CaF2 and the reactant that produced that number will be the limiting reagent.
5. The theoretical yield will be obtained by using the smaller number of moles CaF2 and that times molar mass CaF2.
6. percent yield = (actual yield/theoretical yield)*100 = ??
theoretical yield you obtained in 5. Actual yield is given in the problem as 1.524 g CaF2.
Post your work if you get stuck.
To answer these questions, let's go through them one by one:
(1) Write the equation for the reaction, showing the states of substances:
Ca(NO3)2(aq) + 2NH4F(aq) → CaF2(s) + 2NH4NO3(aq)
(aq) represents aqueous or dissolved in water, and (s) represents a solid.
(2) Calculate the number of moles of Ca(NO3)2 originally present:
We can use the formula: Moles = Concentration (M) × Volume (L)
Moles of Ca(NO3)2 = 4.8724 x 10^(-1) M × 0.04500 L
(3) Calculate the number of moles of NH4F present:
Moles of NH4F = 9.9981 x 10^(-1) M × 0.06000 L
(4) Identify the limiting reagent:
To determine the limiting reagent, we compare the moles of Ca(NO3)2 and NH4F. The reactant that produces fewer moles of the desired product (CaF2) is the limiting reagent.
(5) Calculate the theoretical yield, in grams, of CaF2:
To determine the number of moles of CaF2 produced, we need to use stoichiometry. From the balanced equation, we know that 1 mole of Ca(NO3)2 reacts with 2 moles of NH4F to produce 1 mole of CaF2.
Moles of CaF2 = Moles of Ca(NO3)2 (since the ratio is 1:1)
Then, we can use the molar mass of CaF2 to convert moles to grams:
Theoretical yield of CaF2 = Moles of CaF2 × Molar mass of CaF2
(6) Calculate the percent yield of CaF2:
Percent yield = (Actual yield / Theoretical yield) × 100%
To calculate the actual yield, we are given that 1.524g of CaF2 was isolated.
Now, you can use the above steps to calculate the answers to each question!