Question

4. A new compound X has been made, and a 5 x 10-4 Molar solution of it gives an absorbance of 0.405 at the maximum absorbance of 265 nm. The path length of the UV cell is 0.5cm.
Use Beer’s Law to calculate the Molar Absorptivity coefficient of Compound X at this wavelength, quoting the correct units.

Answer 1

Answer:

1620 cm⁻¹·M⁻¹

Explanation:

Beer's Law states that:

A = ε * b * C

Where A is the absorbance, ε is the Molar Absorptivity coefficient, b is the path length, and C is the molar concentration.

Use the given data:

0.405 = ε * 0.5 cm * 5x10⁻⁴ M

And solve for ε:

ε = 1620 cm⁻¹·M⁻¹

So the Molar Absorptivity coefficient of Compound X at this 265 nm is 1620 cm⁻¹·M⁻¹.