Question

What is the molality of an aqueous KCl solution with a mole fraction of KCl, XKCl = 0.175? (The molar mass of KCl = 74.55 g/mol and the molar mass of H2O is 18.02 g/mol.)

Answer 1

The molality (m) of an aqueous KCl solution with a mole fraction of KCl, XKCl = 0.175, can be calculated using the formula molality (m) = (moles of solute) / (kilograms of solvent). First, calculate the moles of KCl by multiplying the mole fraction by the mass of water and dividing by the molar mass of KCl. Then, calculate the kilograms of water by dividing the mass of water by 1000. Finally, substitute these values into the molality formula.

Step-by-step explanation:

The molality (m) of an aqueous KCl solution with a mole fraction (XKCl) of 0.175 can be calculated using the following formula:

molality (m) = (moles of solute) / (kilograms of solvent)

To find the molality, we need to convert the mole fraction into moles of KCl and kilograms of water. The molar mass of KCl is 74.55 g/mol and the molar mass of H2O is 18.02 g/mol.

First, we calculate the moles of KCl:

moles of KCl = XKCl * (mass of water) / (molar mass of KCl)

Next, we calculate the kilograms of water:

kilograms of water = (mass of water) / 1000

Finally, we substitute these values into the formula:

molality (m) = moles of KCl / kilograms of water