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Hello! I'm completing a lab for chemistry and would like some help on the last bit figuring out concentration then converting to molar mass. I need to make a data chart with a line of best fit on it with the dependent/independent variables. I understand that concentration is on the X-axis and the absorption is on the Y-axis. I used a spectrophotometer to track the different absorbency values of the different dilutions we made. I calibrated the machine using a "Blank" which was water in a test tube. I made a test solution, then made different dilutions using a stock solution provided to my class.
The observation chart that was produced looked like:
Blank (H2O) 0.00 470nm
Test Sol'n 5g solute/25mL H2O 1.41 470nm
Stock Sol'n 0.83 470nm
0.40 mol/L sol'n 12mL S.S./3mL H2O 0.70 470nm
0.30 mol/L sol'n 9mL S.S./6mL H2O 0.58 470nm
0.20 mol/L sol'n 6mL S.S./9mL H2O 0.40 470nm
0.10 mol/L sol'n 3mL S.S./12mL H2O 0.21 470nm
**Sol'n = solution**
**S.S. = stock solution**
**[ ] = concentration**
1. How do you find concentration?
2. How do you convert concentration to molar mass?
The observation chart that was produced looked like:
{Solutions}{Absorbency}{Wavelength (Blue)}
Blank (H2O) 0.00 470nm
Test Sol'n 5g solute/25mL H2O 1.41 470nm
Stock Sol'n 0.83 470nm
0.40 mol/L sol'n 12mL S.S./3mL H2O 0.70 470nm
0.30 mol/L sol'n 9mL S.S./6mL H2O 0.58 470nm
0.20 mol/L sol'n 6mL S.S./9mL H2O 0.40 470nm
0.10 mol/L sol'n 3mL S.S./12mL H2O 0.21 470nm
**Sol'n = solution**
**S.S. = stock solution**
**[ ] = concentration**
1. How do you find concentration?
2. How do you convert concentration to molar mass?
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