Reference no: EM132423964

Problem: Examples and equations may be included in your responses where appropriate. For calculations, clearly show the method used and the steps involved in arriving at your answers. You must show your work to receive credit for your answer. Pay attention to significant figures.

A student has 100. mL of 0.400 M CuSO4(aq) and is asked to make 100. mL of 0.150 M CuSO4(aq) for a spectrophotometry experiment. The following laboratory equipment is available for preparing the solution: centigram balance, weighing paper, funnel, 10 mL beaker, 150 mL beaker, 50 mL graduated cylinder, 100 mL volumetric flask, 50 mL buret, and distilled water.

Question 1: Calculate the volume of 0.400 M CuSO4(aq) required for the preparation.

Question 2: Briefly describe the essential steps to most accurately prepare the 0.150 M CuSO4(aq) from the 0.400 M CuSO4(aq) using the equipment listed above.

The student plans to conduct a spectrophotometric analysis to determine the concentration of Cu2+(aq) in a solution. The solution has a small amount of Co(NO3)2(aq) present as a contaminant. The student is given the diagram below, which shows the absorbance curves for aqueous solutions of Co2+(aq) and Cu2+(aq).

Question 3: The spectrophotometer available to the student has a wavelength range of 400 nm to 700 nm. What wavelength should the student use to minimize the interference from the presence of the Co2+(aq) ions?