1. A 4.277-g sample of Al₂(SO₄)₃ was dissolved in distilled water to make a total volume of 250.0 mL of solution A. Then an aliquot of 25.00 mL of solution A was diluted 10 times with distilled water to give solution B. Determine the molar concentration of the sulfate ions in solution B.

1. A standard solution of FeCl₃ was prepared and its molar concentration was determined to be 2.000 M. This solution was labeled as solution A. Then a 10.00-mL aliquot of solution A was added to a 50.00-mL solution of CoCl₂ of unknown molarity. This solution was labeled as solution B. Finally, 25.00 mL of solution B was transferred to a 500.00-mL volumetric flask and distilled water was added to the calibration mark. This solution was labeled as solution C.

If the concentration of the chlorideions in solution C was found to be 0.08335 M, calculate the molarity of the CoCl₂ solution.

3.A 0.500-L sample of H₂SO₄ solution was analyzed by taking an aliquot of 100.0 mL and reacting it with 50.0 mL of 0.213 M NaOH(aq). After the reaction occurred, the excess base required titration against 13.21 mL of 0.103 M HCl(aq) for complete neutralization.

Calculate the molarity of the original sample of H₂SO₄ solution.