Question

question 9
b. what is the molar concentration of this substance when its absorbance is 0.711 based on the graph in question 7? report your answer as a decimal (not in scientific notation) with two significant figures.

Explanation:

Since the graph from Question 7 is not provided here, we cannot directly calculate the molar - concentration. However, if we assume a linear relationship between absorbance ($A$) and molar concentration ($c$) based on Beer - Lambert's law $A = \epsilon lc$ (where $\epsilon$ is the molar absorptivity and $l$ is the path length), and if we had a calibration curve (the graph in Question 7) of absorbance vs. concentration, we would follow these steps:

Step1: Locate absorbance on the graph

Find the value of 0.711 on the absorbance (y - axis) of the calibration curve.

Step2: Determine corresponding concentration

Draw a horizontal line from the 0.711 absorbance value to the calibration line, then draw a vertical line down to the concentration (x - axis) to read the molar concentration value.

Since we don't have the actual graph, we can't perform the above steps. But if we assume a made - up linear relationship $A=kc$ (where $k$ is a constant), and if we knew $k$, we could solve for $c$ as $c=\frac{A}{k}$.

If we had a calibration curve and after performing the graphical method:

Answer:

(No answer can be provided without the graph from Question 7)