Given:
Substitute 5 g for a mass of solute and 295 g for the mass of solvent and calculate the mass of solution.
As we know,
Mass of solution = mass of solute + mass of solvent
Mass of solution = 5 g +295 g = 300 g
Now, we have a mass solution and also we have given the density of the solution so, calculate the volume of the solution as follows:
Density = mass / volume
volume = mass / Density
Substitute 300 g for a mass of solution and 1.5g/cc for the density of the solution and calculate the volume of the solution.
volume of solution = 300 g / 1.5 g/cc
volume of solution = 200cc
Now, to calculate the moles of solute using the volume of solution and molarity of solution convert the volume of solution in L.
1 L= 1000cc
200cc × 1L/1000cc = 0.2 L
Substitute 0.05 M for molarity and 0.2 L for the volume of solution and calculate the moles of solute as follows:
Molarity = moles of solute / L of solution
Moles of solute = Molarity × L of solution
Moles of solute = 0.05M × 0.2L = 0.01 mol
Now, we have moles of solute and mass of solute so calculate the molecular weight of solute as follows:
molecular weight = mass / mole
Substitute 0.01 mol for moles of solute and 5 g for a mass of solution and calculate the molecular weight of the unknown solute.
Molecular weight = 5 g / 0.01 mol
Molecular weight = 5 g / 0.01 mol
Molecular weight = 500 g/mol
Thus, the molecular weight of the unknown solute is 500 g/mol.