What is the boiling point of the water in your radiator if 2.00kg of antifreeze (ethylene glycol, C2H6O2) is added to 9.00x10^3 grams of water?
triple post.
To determine the boiling point of the water in your radiator after adding antifreeze, you need to use the concept of colligative properties.
Colligative properties are properties of a solution that depend on the number of solute particles, irrespective of their identity. One such property is boiling point elevation, which states that adding a solute to a solvent increases its boiling point.
To calculate the boiling point elevation, you need to use the formula:
△Tb = Kb * m
Where:
△Tb is the boiling point elevation (in °C),
Kb is the molal boiling point elevation constant (in °C•kg/mol),
m is the molality of the solution (in mol/kg).
First, convert the mass of water from grams to kilograms:
Mass of water = 9.00 x 10^3 grams = 9.00 kg
Next, calculate the molality (m) of the solution:
Molality (m) = moles of solute / mass of solvent (in kg)
To find the moles of ethylene glycol (C2H6O2), divide the mass of antifreeze by its molar mass:
Molar mass of ethylene glycol (C2H6O2) = (2 * molar mass of C) + (6 * molar mass of H) + (2 * molar mass of O)
= (2 * 12.01 g/mol) + (6 * 1.01 g/mol) + (2 * 16.00 g/mol)
= 62.07 g/mol
Moles of ethylene glycol (C2H6O2) = mass of antifreeze / molar mass
= 2.00 kg / 62.07 g/mol
Now, calculate the molality (m):
Molality (m) = moles of solute / mass of solvent (in kg)
= (2.00 kg / 62.07 g/mol) / 9.00 kg
With the molality determined, you need the molal boiling point elevation constant (Kb) for water. The Kb value for water is approximately 0.512 °C•kg/mol.
Finally, substitute the values into the boiling point elevation formula:
△Tb = Kb * m
△Tb = (0.512 °C•kg/mol) * [(2.00 kg / 62.07 g/mol) / 9.00 kg]
Simplifying the equation will give you the boiling point elevation (△Tb). To find the boiling point of the water in the radiator, add the boiling point elevation to the normal boiling point of water, which is 100 °C.
By calculating △Tb and adding it to 100 °C, you will get the boiling point of the water in your radiator after adding the antifreeze.