Final answer:
To solve for the mass of PCl3 formed from 20.0 g P and 78.6 g Cl2, we need to know the balanced equation and whether one product is favored over the other; without this information, the mass of PCl3 cannot be accurately calculated.
Step-by-step explanation:
To determine the mass of PCl3 formed from the reaction of 20.0 g of P (phosphorus) and 78.6 g of Cl2 (chlorine gas), we must first establish the molar masses and the stoichiometry of the reaction. The molar mass of Cl2 is 70.90 g/mol; therefore, the moles of Cl2 can be calculated as follows:
(78.6 g Cl2 / 70.90 g/mol Cl2) = 1.108 moles Cl2
The molar mass of P is 30.97 g/mol; thus, the moles of P can be calculated as:
(20.0 g P / 30.97 g/mol P) = 0.646 moles P
The balanced equation for the formation of PCl 3 and PCl 5 as products is:
2 P + 3 Cl2 → 2 PCl3 (Reaction 1)
P + 5 Cl
2
→ PCl
5
(Reaction 2)
However, we do not have enough information to determine the stoichiometry of the specific reaction pathway. If we assume that only PCl3 is formed, then P would be the limiting reagent and the mass of PCl3 could be calculated from the moles of P. If a mixture of PCl3 and PCl5 is formed, we cannot determine the mass of PCl3 without a stoichiometry that describes the ration in which PCl3 and PCl5 form. Therefore, additional information or assumptions are required to solve this problem.