Using the data of 0.3 degrees Celsius freezing point of water-ice mixture, mass of liquid unknown used 7.882g, freezing point of unknown liquid solution -3.5 degrees celsius for trial 1 and -2.9 degrees celsius for trial 2, mass of empty beaker 163.098g and full beaker 233.84 for trial one, and empty beaker with a mass of 163.098g and full beaker with a mass of 238.712g for trial two. Mass of unknown per kg water is 11.14g/kg for trial one and 10.4 g/kg for trial 2. Calculate the molar mass of the unknown liquid for both trials

User Icon for Bot GPT 3.5 Bot GPT 3.5 answered
8 months ago

To calculate the molar mass of the unknown liquid for both trials, we can use the formula:

Molar mass = (mass of unknown liquid / moles of solute) × (1 / mass of solvent)

First, let's calculate the moles of solute for both trials using the given mass of the unknown liquid per kg of water.

For trial 1:
Mass of unknown liquid = 7.882g
Mass of solvent (water) = 233.84g - 163.098g = 70.742g
Mass of solute (unknown liquid) = 7.882g
Mass of solvent in kg = 70.742g / 1000 = 0.070742kg

Moles of solute = Mass of solute / Molar mass of solute
Moles of solute = 7.882g / 11.14g/kg = 0.707 moles

For trial 2:
Mass of unknown liquid = 7.882g
Mass of solvent (water) = 238.712g - 163.098g = 75.614g
Mass of solute (unknown liquid) = 7.882g
Mass of solvent in kg = 75.614g / 1000 = 0.075614kg

Moles of solute = Mass of solute / Molar mass of solute
Moles of solute = 7.882g / 10.4g/kg = 0.758 moles

Now, let's calculate the molar mass of the unknown liquid for both trials.

For trial 1:
Molar mass = (mass of unknown liquid / moles of solute) × (1 / mass of solvent)
Molar mass = (7.882g / 0.707 moles) × (1 / 0.070742kg)
Molar mass = 13.604g/mol

For trial 2:
Molar mass = (mass of unknown liquid / moles of solute) × (1 / mass of solvent)
Molar mass = (7.882g / 0.758 moles) × (1 / 0.075614kg)
Molar mass = 10.434g/mol

Therefore, the molar mass of the unknown liquid is 13.604g/mol for trial 1 and 10.434g/mol for trial 2.