A student prepared $7.2 \mathrm{g}$ of $\mathrm{Co}_{x}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{x}$. She then analyzed the compound by the procedure in this experiment.
A. In the gravimetric determination of chloride, she weighed out a $0.2988-\mathrm{g}$ sample of the product compound. The following data were obtained:
Mass of crucible plus AgCl $19.0020 \mathrm{g}$
Mass of crucible 18.5228 \mathrm{g}
Mass of AgCI __________g MM $\mathrm{AgCl}=143.323 \mathrm{g} / \mathrm{mol}$
Moles of $\mathrm{Cl}^{-}$ in $\mathrm{AgCl}$ __________mol
(Note that this is the moles of Cl present in the 0.2988 g of product compound that the student analyzed.)
Moles Cl per gram of sample __________
B. In the colorimetric determination of cobalt, she used a sample weighing $0.4781 \mathrm{g}$. The molarity of cobalt ion in the solution from the volumetric flask was 0.071 M.
Moles of cobalt ion in $25 \mathrm{mL}$ solution $=$ moles of cobalt in sample __________
Moles of cobalt per gram of sample __________
C. In the volumetric determination of ammonia, the sample weighed $0.9985 \mathrm{g}$. In the titration, $0.1000 \mathrm{M}$ HCI was used. She found that $40.92 \mathrm{mL}$ of the $\mathrm{NH}_{3}$ solution required $35.77 \mathrm{mL}$ of the HCl to reach the endpoint.
Moles of HCl used __________ = moles of $\mathrm{NH}_{3}$ in $40.92 \mathrm{mL}$ of $\mathrm{NH}_{3}$ solution
Moles of $\mathrm{NH}_{3}$ in $250.0 \mathrm{mL}$ NH $_{3}$ solution __________ = moles of $\mathrm{NH}_{3}$ in $0.9985 \mathrm{g}$ of product compound
Moles of $\mathrm{NH}_{3}$ per gram of sample _________
D. Calculation of the formula of $\operatorname{Co}_{x}\left(\mathrm{NH}_{3}\right)_{y} \mathrm{Cl}_{x}$
In $1 \mathrm{g}$ of the product compound (1 g of sample) there are:
moles Co ion = __________
moles $\mathrm{NH}_{3}=$ __________
moles $\mathrm{Cl}^{-}=$ __________
Dividing by smallest number.
moles Co ion __________
moles $\mathrm{NH}_{3}$ __________
moles $\mathrm{Cl}^{-}$ __________
Formula of compound __________
(This may or may not be the formula of the compound you will be making!)