Question

When 3.24 g of a nonelectrolyte solute is dissolved in water to make 955 mL of solution at 22 °C, the solution exerts an osmotic pressure of 973 torr. What is the molar concentration of the solution? concentration: M How many moles of solute are in the solution? moles of solute: mol What is the molar mass of the solute? molar mass: g / mol

Answer 1

Answer:

The molar concentration is 0.0529 M

We have 0.0505 moles solute

The molar mass of the solute is 64.16 g/mol

Explanation:

Step 1: Data given

Mass of the  nonelectrolyte solute = 3.24 grams

Volume of water = 955 mL

Temperature = 22 °C = 295 K

Osmotic pressure = 973 torr = 973 / 760 = 1.28026 atm

Step 2: Calculate mass water

Mass water = 955 mL * 1g/mL

Mass water = 955 grams = 0.955 kg

Step 3: Calculate the molar concentration

π = i*M*R*T

⇒with π = the osmotic pressure = 1.28026 atm

⇒with i = the van't Hoff factor = 1

⇒with M = the molar concentration

⇒with R = the gas constant = 0.08206 L*atm/mol*K

⇒with T = the temperature = 295 K

M = 1.28026 / (0.08206*295)

M = 0.0529 M

Step 4: Calculate moles solute

Molar concentration = moles / volume

Moles solute = Molar concentration * volume

Moles solute = 0.0529 M * 0.955 L

Moles solute = 0.0505 moles

Step 5: Calculate molar mass

Molar mass = mass / moles

Molar mass = 3.24 grams / 0.0505 moles

Molar mass = 64.16 g/mol

The molar concentration is 0.0529 M

We have 0.0505 moles solute

The molar mass of the solute is 64.16 g/mol