if i dissolve 176 grams of ionic compound (particles=3) in 750 got H2O and freezing point to -8.3 degrees Celsius what is the molar mass
To find the molar mass of the ionic compound, we need to use the concept of freezing point depression. Freezing point depression occurs when a solute is added to a solvent, and it causes the freezing point of the solvent to decrease.
The formula to calculate the molar mass is as follows:
Molar mass (g/mol) = (Kf * mass of solute (g)) / (molality * change in freezing point (°C))
Here's how you can solve it step by step:
Step 1: Convert the mass of the solute into moles.
Moles of ionic compound = mass of solute / molar mass
Step 2: Calculate the molality (moles of solute per kg of solvent).
Molality (m) = moles of solute / kilograms of solvent
Convert grams of solvent to kilograms: 750 g = 0.75 kg
Step 3: Determine the change in freezing point.
Change in freezing point (ΔTf) = freezing point of pure solvent - freezing point of solution
The freezing point of pure water is 0°C.
ΔTf = 0°C - (-8.3°C) = 8.3°C
Step 4: Plug the values into the formula to find the molar mass.
Molar mass = (Kf * mass of solute) / (molality * change in freezing point)
Kf is the cryoscopic constant, which depends on the solvent. For water, Kf = 1.86°C·kg/mol.
Molar mass = (1.86°C·kg/mol * mass of solute) / (molality * 8.3°C)
Note: Since you mentioned the number of particles (ions) in the formula as 3, it suggests that the ionic compound may be a salt, and it dissociates into three ions in water.
By following these steps, you can obtain the molar mass of the ionic compound.