Question

What is the numerical value of the molality of a solution containing 122 g of MgSO4 in 3.5 L of solution?Answers to choose:•0.550•0.630•0.300•0.290

Answer 1

Molarity or molar concentration is a measure of the concentration of a chemical species, of a solute in a solution, using as units, number of moles, and volume in liters. The formula for Molarity is:

M = n/V

Where:

n = number of moles

V = volume in Liters

But in this question we don't have the number of moles yet, so we need to use the given mass and also the molar mass of MgSO4, which is 120.366g/mol

120.366g = 1 mol

122g = x moles

x = 1.013 moles of MgSO4

Now we can use the molarity formula:

M = 1.013/3.5

M = 0.290 is the concentration