A chemist prepares a solution of calcium bromide (CaBr2) by measuring out 0.54 kg of calcium bromide into a 350 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist’s calcium bromide solution. Round your answer to 2 significant digits
To calculate the concentration in mol/L, we need to first calculate the number of moles of calcium bromide in the solution.
The molar mass of calcium bromide (CaBr2) is 199.89 g/mol.
First, we convert the mass of calcium bromide from kilograms to grams:
0.54 kg = 540 g
Next, we calculate the number of moles using the formula:
moles = mass / molar mass
moles = 540 g / 199.89 g/mol
moles ≈ 2.70 mol
Now, we need to calculate the volume of the solution in liters using the volumetric flask. The volume given is 350 mL, which is equivalent to 0.350 L.
Finally, we calculate the concentration in mol/L by dividing the number of moles by the volume in liters:
concentration = moles / volume
concentration = 2.70 mol / 0.350 L
concentration ≈ 7.71 mol/L
Rounding up to 2 significant digits, the concentration of the calcium bromide solution is approximately 7.7 mol/L.