4. how are absorbance and concentration related? explain.

Brief Explanations:

According to Beer - Lambert law, absorbance (A) is directly proportional to the concentration (c) of the absorbing species in a solution when the path - length (l) and the molar absorptivity (ε) are constant. The formula is $A=\varepsilon lc$. As the concentration of the absorbing substance increases, more light is absorbed, and the absorbance value goes up.

Answer:

Absorbance is directly proportional to concentration according to Beer - Lambert law ($A = \varepsilon lc$), where $A$ is absorbance, $\varepsilon$ is molar absorptivity, $l$ is path - length, and $c$ is concentration. When $\varepsilon$ and $l$ are constant, an increase in $c$ leads to an increase in $A$.