Final answer: The concentration of the chemist's aluminum sulfate solution is 176.5 g/L.
Step-by-step explanation:To calculate the concentration of the aluminum sulfate solution, we need to divide the mass of the solute by the volume of the solution.
In this case, the mass of the aluminum sulfate is 70.6 g and the volume of the solution is 400 mL, which is equivalent to 0.400 L.Dividing the mass by the volume gives us a concentration of 176.5 g/L. Therefore, the correct answer is option a, which is 176.5 g/L.