A 47.7-g sample of SrCl2 is dissolved in 112.5 mL of solution. Calculate the molarity of this solution.
2.67 M
moles = grams/molar mass
solve for moles.
M = moles/L
solve for M.
To calculate the molarity of a solution, we need to know the number of moles of solute and the volume of the solution in liters.
First, we need to convert the mass of SrCl2 to moles. We will use the molar mass of SrCl2 to do this.
The molar mass of SrCl2 is:
(1 x atomic mass of Sr) + (2 x atomic mass of Cl)
(1 x 87.62 g/mol) + (2 x 35.45 g/mol)
87.62 g/mol + 70.90 g/mol
158.52 g/mol
To convert the mass of SrCl2 to moles, we use the formula:
moles = mass / molar mass
moles = 47.7 g / 158.52 g/mol
moles = 0.301 mol
Next, we need to convert the volume of the solution from milliliters to liters. There are 1000 mL in 1 L, so:
volume of solution (in liters) = 112.5 mL / 1000
volume of solution (in liters) = 0.1125 L
Now that we have the number of moles of SrCl2 (0.301 mol) and the volume of the solution in liters (0.1125 L), we can calculate the molarity using the formula:
molarity = moles of solute / volume of solution (in liters)
molarity = 0.301 mol / 0.1125 L
molarity ≈ 2.68 M
Therefore, the molarity of the solution is approximately 2.68 M.
To calculate the molarity of the solution, we need to determine the number of moles of SrCl2 and the volume of the solution in liters.
1. Calculate the number of moles of SrCl2:
Molar mass of SrCl2 = (atomic mass of Sr) + 2 × (atomic mass of Cl)
= (87.62 g/mol) + 2 × (35.45 g/mol)
= 87.62 g/mol + 70.90 g/mol
= 158.52 g/mol
Number of moles = mass / molar mass
= 47.7 g / 158.52 g/mol
≈ 0.301 moles of SrCl2
2. Convert the volume of the solution from milliliters to liters:
112.5 mL = 112.5 mL × (1 L / 1000 mL)
= 0.1125 L
3. Calculate the molarity:
Molarity (M) = moles of solute / volume of solution (in liters)
= 0.301 moles / 0.1125 L
≈ 2.68 M
Therefore, the molarity of the solution is approximately 2.68 M.