Question

How would I find the answers for the last column?

Answer 1

To calculate the concentration [FeNCS+2] we use the data shown in the curve (Absorbance vs Concentration).

As we can see, the linear equation for absorbance at 447.1nm, given the values of m and b is:

`Abs=5748X-0.05559`

Where X is the concentration [FeNCS+2] in mol/L.

In the table we are given the values of absorbance and we need to calculate the corresponding concentration. Therefore we rearrange the equation:

`X=(Abs+0.05559)/(5748)`

Now we only have to use the absorbance values given in the table to calculate the concentration. The values and results are:

`\begin{gathered} Absorbance:\text{ 0.218} \\ Concentration:4.76 \\ \\ Absorbance:0.256 \\ Concentration:5.42 \\ \\ Absorbance\text{: 0.366} \\ Concentration:7.33 \\ \\ Absorbance:0.337 \\ Concentration:6.83 \end{gathered}`