Question

Be sure to answer all parts.

Absorbance values for five standard solutions of a colored solute were determined at 410 nm with a 1.00−cm path length, giving the following table of data:

Solute concentration (M)	A
0.250	0.100
0.500	0.200
0.750	0.300
1.000	0.400
1.250	0.500

Determine the absorbance values you would expect for solutions with the following concentrations:

0.4 M

______

0.6 M

______

0.8 M

______

1.1 M

______

Calculate the average molar absorptivity of the compound.

_____ 1/(M*cm)

Answer 1

Determine the absorbance values you would expect for solutions with the following concentrations:

We have the straight line equation from the graph    y = 0.4x - 5.5 x 10^-17

a) 0.4 M

Applying the straight line equation,

Absorbance = 0.4 x 0.4 - 5.5 x 10^-17 = 0.16

b) 0.6 M

Absorbance = 0.4 x 0.6 - 5.5 x 10^-17 = 0.24

c) 0.8 M

Absorbance = 0.4 x 0.8 - 5.5 x 10^-17 = 0.32

d) 1.1 M

Absorbance = 0.4 x 1.1 - 5.5 x 10^-17 = 0.44

Average molar absorptivity of the compound = Slope of the graph/ Path length

                                                                         = 0.4 M^-1cm^-1