Question

Using the equation y=0.0165x in the figure below, where y= absorbance and x= concentration in mmol/L, calculate the concentraion of Cu2+ in a sample whose absorbance is 0.275. Show your work, and include correct unit for concentration

0.350 0.300 0.250 y = 0.0165x R = 0.9983 unk 0 U 0.200 0.150 0.100 0.050 0.000 0.0 5.0 10.0 15.0 Cunk 20.0 25.0 Concentration of Cu2+ standards, mmol/L

Answer 1

Answer

16.67mmol/L

Explanation

staight line equation is

y = mx + c

where,

m = slope

c = y intercept

the given equation is

y = 0.0165x

y= Absorbance

x = concentration

slope = 0.0165

y intercept = 0

substituting the absorbance value

0.275 = 0.0165x

x = 0.275/0.0165 = 16.67mmol/L