Final answer:
To find the mass of 2.864 moles of Co(NH3)6Cl3, the correct molar mass must first be calculated, and then this molar mass is used to convert moles to grams, resulting in a mass of 765.785 g.
Step-by-step explanation:
To calculate the mass of 2.864 moles of the compound Co(NH3)6Cl3, we first need to determine the molar mass of the compound. However, the molar mass provided in the information (176.124 g/mol) appears to be incorrect for Co(NH3)6Cl3, as its actual molar mass is significantly higher due to the presence of multiple heavy atoms like Co and Cl, along with six NH3 groups. Hence we'll need to calculate the molar mass correctly first:
- Co: 58.93 g/mol
- NH3 (17.03 g/mol each) x 6 = 102.18 g/mol
- Cl (35.45 g/mol each) x 3 = 106.35 g/mol
Add these together to get the correct molar mass for Co(NH3)6Cl3:
58.93 g/mol + 102.18 g/mol + 106.35 g/mol = 267.46 g/mol
Then, use the molar mass to convert moles to grams:
Mass = moles x molar mass = 2.864 moles x 267.46 g/mol = 765.785 g (rounded to three significant figures)