23.9 g of CaCl2 (MM = 111.0 g/mol) is dissolved in enough water to make 300. mL of solution. What is the molarity of the solution?
mols CaCl2 = grams/molar mass
M CaCl2 solution = mols CaCl2/L solution.
To find the molarity of a solution, use the formula:
Molarity (M) = moles of solute / volume of solution in liters
First, let's calculate the moles of CaCl2 using the given mass and molar mass:
moles of CaCl2 = mass of CaCl2 / molar mass
= 23.9 g / 111.0 g/mol
moles of CaCl2 = 0.215 g
Next, convert the volume of the solution to liters:
volume of solution = 300 mL = 0.3 L
Finally, substitute the values into the formula to find the molarity:
Molarity (M) = 0.215 mol / 0.3 L
≈ 0.716 M
Therefore, the molarity of the solution is approximately 0.716 M.
To find the molarity of the solution, we need to divide the number of moles of CaCl2 by the volume of the solution in liters.
First, let's calculate the number of moles of CaCl2 in the solution.
Given:
Mass of CaCl2 = 23.9 g
Molar mass of CaCl2 = 111.0 g/mol
To find the moles, we use the formula:
moles = mass / molar mass
moles of CaCl2 = 23.9 g / 111.0 g/mol
moles of CaCl2 ≈ 0.215 g/mol
Next, we need to convert the volume of the solution to liters.
Given:
Volume of solution = 300. mL
To convert the volume from mL to liters, we use the conversion factor:
1 L = 1000 mL
Volume of solution = 300. mL × (1 L / 1000 mL)
Volume of solution = 0.300 L
Now, we can find the molarity using the formula:
molarity = moles / volume
Molarity = 0.215 mol / 0.300 L
Molarity ≈ 0.72 mol/L
Therefore, the molarity of the solution is approximately 0.72 mol/L.