Final answer:
In 0.17 grams of PCl5, there are approximately 8.17 x 10⁻⁴ moles, calculated by dividing the mass of PCl₅ by its molar mass of 208.24 g/mol.
Step-by-step explanation:
To determine how many moles of PCl5 are in 0.17 g of PCl₅, you need to use the compound's molar mass. The molar mass of PCl₅ is calculated to be 208.24 g/mol. Using this information, you can calculate the number of moles (mol) by dividing the mass of the substance by its molar mass.
The formula to calculate moles is:
Number of moles = Mass (g) ÷ Molar mass (g/mol)
For PCl₅:
Number of moles = 0.17 g ÷ 208.24 g/mol
= 8.17 × 10⁻⁴ mol
Therefore, there are approximately 8.17 × 10⁻⁴ moles of PCl₅ in 0.17 grams of the substance.