(d) calculate the molar absorptivity (ε) of cu2+ at 620 nm given that the cuvettes used in lab had a pathlength of 1.00 cm.

The working equation to be used for our calculations is taken from Beer's Law which is about the absorption of light by the particles in a solution. The equation is written below.

A = ∈LC
where
A is the absorbance
∈ is the molar absorptivity
L is the path length
C is the molar concentration of the solution

Solving for ∈,

∈ = A/LC = A/(1)(C) = A/C

Therefore, the molar absorptivity is equal to the absorbance divided by the molar concentration. (I can't give an exact answer because A and C are not specified)

They are all solids.