Absorbances of a series of phosphate standard solutions measured using UV-Vis spectrophotometer using 1.0 cm pathlength glass cuvette at 415 nm aregiven in table 2 below.7.Table 2Standard solutionConcentration (mmol/L)AbsorbanceStd 10.00.1Std 20.15Std 30.20.28Std 40.30.4Std 50.40.55Std 60.50.7If an unknown sample exhibits an absorbance of 0.45. Determine thephosphate concentration in this unknown sample solution, using:a)Calibration plotb)Least-square method

A question based on concentration, which is to be accomplished.

Absorbances of a series of phosphate standard solutions measured using UV- Vis spectrophotometer using 1.0 cm pathlength glass cuvette at 415 nm are given in table 2 below. Table 2 Standard solution Concentration (mmol/L) Absorbance Std 1 Std 2 0.0 0.1 0.15 Std 3 Std 4 0.2 0.3 0.28 0.4 Std 5 0.4 0.55 0.7 Std 6 0.5 If an unknown sample exhibits an absorbance of 0.45. Determine the phosphate concentration in this unknown sample solution, using: a) Calibration plot b) Least-square method