5. A 0.500 g sample of a BaCl2•2H2O/Na2SO4 salt mixture, when mixed with water, filtered, and dried, produced 0.225 g of BaSO4. The Na2SO4 was determined to be the limiting reactant.
a. Calculate the mass, in grams, of Na2SO4 in the mixture.
b. Calculate the mass, in grams, of BaCl2•2H2O in the mixture.
c. What is the percentage of Na2SO4 and BaCl2•2H2O in the salt mixture?
a. Write the equation and balance it.
mols BaSO4 = grams/molar mass
Using the coefficients in the balanced equation, convert mols BaSO4 to mols Na2SO4.
Now convert mols Na2SO4 to g. g = mols x molar mass.
b. 0.500g - mass Na2SO4 = g BaCl2.2H2O
c. %Na2SO4 = (g Na2SO4/0.500)*100 = ?
%BaCl2.2H2O = 100% - % Na2SO4.
5. A 0.500 g sample of a BaCl2•2H2O/Na2SO4 salt mixture, when mixed with water, filtered, and dried, produced 0.225 g of BaSO4. The Na2SO4 was determined to be the limiting reactant.
a. Calculate the mass, in grams, of Na2SO4 in the mixture.
b. Calculate the mass, in grams, of BaCl2•2H2O in the mixture.
c. What is the percentage of Na2SO4 and BaCl2•2H2O in the salt mixture?
To solve this problem, we will use the concept of stoichiometry and the balanced chemical equation between BaCl2 and Na2SO4 to determine the masses of Na2SO4 and BaCl2•2H2O in the given salt mixture.
a. To calculate the mass of Na2SO4 in the mixture:
1. Determine the molar mass of BaSO4 by summing the atomic masses of its constituent atoms. BaSO4 consists of one Ba atom (molar mass = 137.33 g/mol), one S atom (molar mass = 32.06 g/mol), and four O atoms (molar mass = 16.00 g/mol). Therefore, the molar mass of BaSO4 is 137.33 g/mol + 32.06 g/mol + (4 × 16.00 g/mol) = 233.39 g/mol.
2. Use the balanced chemical equation between BaCl2 and Na2SO4 to determine the stoichiometric ratio of BaSO4 to Na2SO4. The balanced chemical equation is:
BaCl2 + Na2SO4 → BaSO4 + 2NaCl
From the equation, we can see that the stoichiometric ratio between BaSO4 and Na2SO4 is 1:1. Therefore, the moles of Na2SO4 in the mixture are equal to the moles of BaSO4 in the mixture.
3. Calculate the moles of Na2SO4 in the mixture using the given mass of BaSO4. The mass of BaSO4 produced is 0.225 g. To convert this mass to moles, we need to divide it by the molar mass of BaSO4:
moles of BaSO4 = mass of BaSO4 / molar mass of BaSO4
moles of BaSO4 = 0.225 g / 233.39 g/mol
4. Since the stoichiometric ratio between BaSO4 and Na2SO4 is 1:1, the moles of Na2SO4 in the mixture will be the same as the moles of BaSO4. Therefore, the moles of Na2SO4 in the mixture are also 0.225 g / 233.39 g/mol.
5. Convert the moles of Na2SO4 back into grams by multiplying by the molar mass of Na2SO4, which is 142.04 g/mol:
mass of Na2SO4 = moles of Na2SO4 × molar mass of Na2SO4
mass of Na2SO4 = (0.225 g / 233.39 g/mol) × 142.04 g/mol
b. To calculate the mass of BaCl2•2H2O in the mixture:
1. Calculate the mass of BaSO4 in the mixture using the given mass of BaSO4: mass of BaSO4 = 0.225 g.
2. Calculate the mass of BaCl2 by subtracting the mass of BaSO4 from the total mass of the mixture: mass of BaCl2 = mass of the mixture - mass of BaSO4.
mass of BaCl2 = 0.500 g - 0.225 g
3. The BaCl2•2H2O compound contains one Ba, two Cl, and two H2O molecules. Calculate the molar mass of BaCl2•2H2O by summing the atomic masses of its constituent elements (Ba, Cl, H, and O). The molar mass of BaCl2•2H2O is equal to: (Ba atomic mass) + 2 × (Cl atomic mass) + 2 × (H atomic mass) + 2 × (O atomic mass).
4. Use the molar mass of BaCl2•2H2O to convert the calculated mass of BaCl2 into moles.
5. Convert the moles of BaCl2 back into grams by multiplying by the molar mass of BaCl2.
c. To calculate the percentage of Na2SO4 and BaCl2•2H2O in the salt mixture:
1. The total mass of the salt mixture is 0.500 g.
2. Calculate the percentage of Na2SO4 in the salt mixture by dividing the mass of Na2SO4 by the total mass of the mixture and multiplying by 100%:
percentage of Na2SO4 = (mass of Na2SO4 / total mass of the mixture) × 100%
3. Calculate the percentage of BaCl2•2H2O in the salt mixture by dividing the mass of BaCl2•2H2O by the total mass of the mixture and multiplying by 100%:
percentage of BaCl2•2H2O = (mass of BaCl2•2H2O / total mass of the mixture) × 100%
By following these steps, you should be able to calculate the mass of Na2SO4 and BaCl2•2H2O in the mixture, as well as the percentage of each compound in the salt mixture.