Final answer:
The factor that causes a change in absorbance (E) according to Beer's Law is the concentration of the solute in the solution. Beer's Law indicates a direct proportionality between absorbance and solute concentration.
Step-by-step explanation:
According to Beer's Law, the change in absorbance (E) at a given wavelength is directly proportional to the concentration of the solute in the solution. Beer's Law, also known as Lambert-Beer law, establishes a relationship where the absorbance is equal to the product of the molar absorptivity coefficient (ε), the concentration (c), and the path length (l). This relationship is expressed by the formula A = εcl. The primary factor that causes a change in E (absorbance) is the concentration of the solute. The temperature, pressure, and volume of the solvent may affect the physical properties of the solution or reaction rates, but they do not alter the linear relationship between concentration and absorbance described by Beer's Law. Therefore, option 1) Concentration of the solute is the correct answer to what affects the change in E according to Beer's Law.