Question

Calculate the molarity of a solution in which enough water is added to 244.0 g of magnesium bromide to make a solution with a volume of 1.36 L?

Answer 1

To find the molarity of a magnesium bromide solution with 244.0 g in 1.36 L of water, convert the mass to moles using magnesium bromide's molar mass (184.11 g/mol), resulting in 1.325 moles. Then divide the moles by the volume to get 0.974 M.

Step-by-step explanation:

To calculate the molarity of a magnesium bromide solution where 244.0 g of solute is dissolved in 1.36 L of water, we first need to find the molar mass of magnesium bromide (MgBr2). Magnesium (Mg) has an atomic mass of approximately 24.31 g/mol and bromine (Br) has an atomic mass of approximately 79.90 g/mol. Since there are two bromine atoms in magnesium bromide, we can calculate its molar mass as following:

• Molar mass of MgBr2 = 24.31 g/mol (Mg) + 2 × 79.90 g/mol (Br) = 24.31 g/mol + 159.80 g/mol = 184.11 g/mol

Next, we convert the mass of magnesium bromide to moles:

• Moles of MgBr2 = 244.0 g ÷ 184.11 g/mol = 1.325 moles

Finally, we divide the number of moles by the volume of the solution in liters to get the molarity:

• Molarity (M) = 1.325 moles ÷ 1.36 L = 0.9743 M, which can be rounded to 0.974 M