Phosphate Unknown Known values: Volume Used 5.0 ml of unknown Phosphate. 5 ml of
ID: 783099 • Letter: P
Question
Phosphate Unknown
Known values:
Volume Used 5.0 ml of unknown Phosphate.
5 ml of NH4MoO4
and 10 ml of HNO3
diluted in 100 ml of volumetric flask.
Absorbance of unknown - 0.464
In other part of the lab, I did other experiment with standard phosphate solution: And calculated its concentration and individual standards that were prepared. Not sure if they there are needed. I could give those values if needed.
Need help with following data:
Absorbance of measured solution: ? (should it be 0.464)
Concentration of measured solution(from plot): mM?
Concentration of Phosphate Unknown: mM?
Please show steps and ask if any other values are needed.
Thank you.
Explanation / Answer
Absorbance is directly proportional with concentration.A=%u03B5cl,where A=absorbance c=conc.l path length %u03B5=molar extinction coefficient.So if u increase the phosphate concetration the absorbance will increase.And u can calculate unknown concentration of phosphate by measuring absobance of phosphate of differenrent in concetration then take absorbance of unknown conc.and plot it absorbance vs Concentration ,then you will get straight line .and select the unknown absobance value of phosphate,and get its conncentration in x-axis.