Question

A student prepares a solution by dissolving 20.0 g of aluminum chloride (AlCl3) in enough water to produce 500 mL of solution. What is the molarity of the solution?

Answer 1

The molarity (M) of a solution is calculated by dividing the moles of solute by the volume of solution in liters.

First, we need to calculate the moles of aluminum chloride:

moles of AlCl3 = mass / molar mass

moles of AlCl3 = 20.0 g / 133.34 g/mol

moles of AlCl3 = 0.150 mol

Next, we need to convert the volume of solution from milliliters to liters:

volume of solution = 500 mL / 1000 mL/L

volume of solution = 0.500 L

Finally, we can calculate the molarity of the solution:

Molarity = moles of solute / volume of solution

Molarity = 0.150 mol / 0.500 L

Molarity = 0.30 M

Therefore, the molarity of the aluminum chloride solution is 0.30 M.