Problem:

What volume of 5M Na2SO4 must be added to 25ml of 1M BaCl2 to produce 10g of BaSO4?

Solution:

To solve this problem, we will follow these steps:

1. Calculate the moles of BaCl2 present in 25ml of 1M BaCl2.
2. Use the stoichiometry of the reaction between BaCl2 and Na2SO4 to determine the moles of Na2SO4 required to produce 10g of BaSO4.
3. Convert the moles of Na2SO4 to the required volume of 5M Na2SO4 solution using its molarity.

Step 1: Calculate the moles of BaCl2 present in 25ml of 1M BaCl2.

The molarity of a solution is given by the formula:

Molarity (M) = moles of solute / volume of solution (in liters)

Given that the volume of 1M BaCl2 solution is 25ml (0.025L) and the molarity is 1M, we can rearrange the formula to solve for moles of solute:

moles of BaCl2 = Molarity x volume of solution

moles of BaCl2 = 1M x 0.025L

moles of BaCl2 = 0.025 moles

Step 2: Use the stoichiometry of the reaction between BaCl2 and Na2SO4 to determine the moles of Na2SO4 required to produce 10g of BaSO4.

The balanced chemical equation for the reaction between BaCl2 and Na2SO4 is:

BaCl2 + Na2SO4 -> BaSO4 + 2NaCl

From the equation, we can see that 1 mole of BaCl2 reacts with 1 mole of Na2SO4 to produce 1 mole of BaSO4.

10g of BaSO4 is equivalent to:

moles of BaSO4 = mass / molar mass

moles of BaSO4 = 10g / (137.33g/mol)

moles of BaSO4 = 0.0727 moles

Therefore, 0.0727 moles of Na2SO4 are required to produce 10g of BaSO4.

Step 3: Convert the moles of Na2SO4 to the required volume of 5M Na2SO4 solution using its molarity.

The molarity of a solution is given by the formula:

Molarity (M) = moles of solute / volume of solution (in liters)

We can rearrange the formula to solve for the volume of solution:

volume of solution = moles of solute / Molarity

volume of 5M Na2SO4 solution = 0.0727 moles / 5M

volume of 5M Na2SO4 solution = 0.0145 L = 14.5 ml

Therefore, 14.5ml of 5M Na2SO4 solution must be added to 25ml of 1M BaCl2 to produce 10g of BaSO4.

Apply M1V1+M2V2=M3V3