Question

A copper sulfate solution of unknown concentration is placed in a spectrophotometer and an absorbance reading of 0.460 is recorded. A 0.55M copper sulfate solution gives an absorbance reading of 0.340. What is the concentration of the first solution?

Answer 1

The concentration of the unknown copper sulfate solution is determined by setting up a proportion based on the known concentration and absorbance and solving for the unknown concentration, which is approximately 0.744M.

Step-by-step explanation:

The question involves using spectrophotometric data to determine the concentration of an unknown copper sulfate solution. Since the relationship between absorbance and concentration is linear (as per Beer-Lambert Law), we can set up a proportion based on the known concentration and its absorbance. The known solution has a concentration of 0.55M and an absorbance of 0.340. The unknown solution has an absorbance of 0.460. Using the direct proportion:

0.55M / 0.340 = xM / 0.460,

we can solve for the unknown concentration 'x'.

x = (0.460 × 0.55M) / 0.340,

x ≈ 0.744M.

The concentration of the unknown copper sulfate solution is approximately 0.744M.