Answer:
The molar mass of propylamine (C3H9N) can be calculated as follows:
Molar mass of C3H9N = (3 × molar mass of C) + (9 × molar mass of H) + (1 × molar mass of N)
= (3 × 12.01 g/mol) + (9 × 1.01 g/mol) + (1 × 14.01 g/mol)
= 59.11 g/mol
This means that one mole of propylamine has a mass of 59.11 g.
To find the mass of 4.21×1024 molecules of propylamine, we can use the following steps:
Determine the number of moles of propylamine in 4.21×1024 molecules:
Number of moles = Number of molecules ÷ Avogadro's number
= 4.21×1024 ÷ 6.022 × 10^23
= 6.997 mol (rounded to three decimal places)
Calculate the mass of 6.997 moles of propylamine:
Mass = Number of moles × Molar mass
= 6.997 mol × 59.11 g/mol
= 413.9 g (rounded to one decimal place)
Therefore, the mass of 4.21×1024 molecules of propylamine is 413.9 g.