Calculate the molality of a 20.0% by mass ammonium sulfate (NH4)2SO4 The density of the solution is 1.117 g/mL.Group of answer choices4.48 m7.98 m8.43 m8.10 m10.2 m

To calculate the molality of a solution, we need to know the mass of the solute (in this case, ammonium sulfate (NH4)2SO4), the mass of the solvent (water), and the molecular weight of the solute.

1. First, let's calculate the mass of the solute and the solvent. Since the solution is 20.0% by mass ammonium sulfate, this means that in 100 g of solution, there are 20 g of ammonium sulfate and 80 g of water.

2. Next, we need to convert the mass of water from grams to kilograms, since molality is defined as the number of moles of solute per kilogram of solvent. 80 g of water is equivalent to 0.080 kg.

3. Now, we need to calculate the number of moles of ammonium sulfate. The molecular weight of ammonium sulfate is approximately 132.14 g/mol. So, 20 g of ammonium sulfate is equivalent to 20 g / 132.14 g/mol = 0.151 mol.

4. Finally, we can calculate the molality of the solution by dividing the number of moles of solute by the mass of the solvent in kilograms. So, the molality of the solution is 0.151 mol / 0.080 kg = 1.89 m.

None of the provided answer choices match this result, so there may be a mistake in the question or the answer choices.