determination of observed molar mass of solute
Answers
Explanation:
can use a measurement of any one of the following properties to determine the molar mass (molecular weight) of an unknown that is the solute in a solution:
Boiling Point Elevation
Freezing Point Depression
Osmotic Pressure
From Boiling Point Elevation
Determine the change in boiling point from the observed boiling point of the solution and the boiling point of the pure solvent.
Equation for delta t
Determine the molal concentration, m, from the change in boiling point and the boiling point elevation constant.
Equation to determine molality
Determine the moles of unknown (the solute) from the molality of the solution and the mass of solvent (in kilograms) used to make the solution.
Equation for calculating molality
Equation for calculating moles from molality
Determine the molar mass from the mass of the unknown and the number of moles of unknown.
From Boiling Point Elevation
Determine the change in boiling point from the observed boiling point of the solution and the boiling point of the pure solvent.
Equation for delta t
Determine the molal concentration, m, from the change in boiling point and the boiling point elevation constant.
Equation to determine molality
Determine the moles of unknown (the solute) from the molality of the solution and the mass of solvent (in kilograms) used to make the solution.
Equation for calculating molality
Equation for calculating moles from molality
Determine the molar mass from the mass of the unknown and the number of moles of unknown.
Equation for calculating Molar mass from moles
Top
From Freezing Point Depression
Determine the change in freezing point from the observed freezing point of the solution and the freezing point of the pure solvent. (This will be a negative number.)
Equation for delta t
Determine the molal concentration, m, from the change in freezing point and the freezing point depression constant.
Equation for molality from f.p. depression
Determine the moles of unknown (the solute) from the molality of the solution and the mass of solvent (in kilograms) used to make the solution.
Equation for calculating molality
Equation for calculating moles from molality
Determine the molar mass from the mass of the unknown and the number of moles of unknown.
Equation for calculating Molar mass from moles
Top
From Osmotic Pressure
Determine the molar concentration of the unknown in the solution from the observed osmotic pressure.
Equation for osmotic pressure
Equation for calculating molarity from omotic pressure
Determine the moles of unknown (the solute) from the molarity of the solution and the volume (in liters) of the solution.
Equation for calculating molalrity
Equation for calculating moles from molarity
Determine the molar mass from the mass of the unknown and the number of moles of unknown.