I'm doing an experiment to measure the light absorbance of bromophenol blue? (spectrophotometry)

i have 5 test tubes: 1st) 1ml BB and 4ml H2O 2nd) 2ml BB and 3ml H2O 3rd) 3ml BB and 2ml H2O 4th) 4ml BB and 1ml h2O and the 5th) 5ml BB and 0ml H2O.

max absorbency at wavelength 595 nm

concentration of stock solution: 10mg/L

results are: 1st tube: .332

2nd tube: .368

3rd tube: .375

4th tube: .533

5th tube: .746

 

how can i draw a graph concentration of bromophenol blue (x-axis) and absorbance (y-axis)? then i need to find the absorbance at concentration 2, 4, 6, 8, 10?

 

please i need detailed steps

Edited July 16, 201114 yr by Devoy

Are those "results" absorbances or extinction coefficients?

i need to find the absorbance at concentration 2, 4, 6, 8, 10?

What units?

Do you have the concentration of the stock solution of BB?

 

I'm doing an experiment to measure the light absorbance of bromophenol blue? (spectrophotometry)

i have 5 test tubes: 1st) 1ml BB and 4ml H2O 2nd) 2ml BB and 3ml H2O 3rd) 3ml BB and 2ml H2O 4th) 4ml BB and 1ml h2O and the 5th) 5ml BB and 0ml H2O.

max absorbency at wavelength 595 nm

concentration of stock solution: 10mg/L

results are: 1st tube: .332

2nd tube: .368

3rd tube: .375

4th tube: .533

5th tube: .746

 

how can i draw a graph concentration of bromophenol blue (x-axis) and absorbance (y-axis)? then i need to find the absorbance at concentration 2, 4, 6, 8, 10?

 

please i need detailed steps

Do you have the concentration of the stock solution of BB?

 

"max absorbency at wavelength 595 nm

concentration of stock solution: 10mg/L

results are: 1st tube: .332 "

Here are the main steps:

1 - Calculate the concentration of BB on the standards (the 5 tubes you have used). Thhey are just dilutions of the stock solution;

2 - Plot the values of the concentration (usually on x axis) and the values of the absorbance (y axis);

3 - Determine the equation obtained from the linear relationship between concentration and absorbance. In that equation, the x means concentration and the y absorbance.

4 - Substitute in the equation the x for the values of the concentrations you need to, and calculate the absorbance values.

 

I'm doing an experiment to measure the light absorbance of bromophenol blue? (spectrophotometry)

i have 5 test tubes: 1st) 1ml BB and 4ml H2O 2nd) 2ml BB and 3ml H2O 3rd) 3ml BB and 2ml H2O 4th) 4ml BB and 1ml h2O and the 5th) 5ml BB and 0ml H2O.

max absorbency at wavelength 595 nm

concentration of stock solution: 10mg/L

results are: 1st tube: .332

2nd tube: .368

3rd tube: .375

4th tube: .533

5th tube: .746

 

how can i draw a graph concentration of bromophenol blue (x-axis) and absorbance (y-axis)? then i need to find the absorbance at concentration 2, 4, 6, 8, 10?

 

please i need detailed steps

The real problem here is that the data are lousy.

The 3 highest concentrations are pretty much on a straight line through the origin, but the low concentration ones are odd. They are all too high.

Was a proper blank used?