Question

Copper(II) forms a 1:1 complex with the organic complexing agent R in acidic medium. The formation of the complex can be monitored by spectrophotometry at 480 nm. Use the following data collected under pseudo-first-order conditions to construct a calibration curve of rate versus concentration of R. Find the concentration of copper(II) in an unknown whose rate under the same conditions was 6.2 x 10 ^-3 A s ^-1.

Short answer

The concentration of copper(II) in an unknown whose rate under the same conditions was 6.2 x 10 ^-3 A s ^-1is 5.62 ppm

Step-by-step solution

Given Information

Explanation

The plot between concentration and absorbance is:

According to the graph, the equation of the graph is

$$\begin{gathered} \mathrm{y}=0.011\mathrm{x}+2\times {10}^{-5} \\ 6.2\times {10}^{-3}\mathrm{A}{\mathrm{s}}^{-1}=0.0011\mathrm{x}+2\times {10}^{-5} \\ 0.0011\mathrm{x}=6.2\times {10}^{-3}-2\times {10}^{-5} \\ 0.0011\mathrm{x}=6.18\times {10}^{-3} \\ \mathrm{x}=5.62\mathrm{ppm} \end{gathered}$$