The molar mass of a substance can be calculated using this formula:
molar mass = mass of the subtance/number of moles
We know the mass of the sample and the number of moles present in that sample, so we can use that formula to get the answer to our problem.
mass of the substance = 28.84 g
number of moles = 0.8441 moles
molar mass = mass of the subtance/number of moles
molar mass = 28.84 g/(0.8441 moles)
molar mass = 34.17 g/mol
Answer: the molar mass of the substance is 34.17 g/mol.