Question

A 10.00 ml volume of soft drink is treated with acid and molybdate and diluted to 100.00 ml. Its absorbance is measured. From the following data, calculate the concentration of phosphate in the soft drink (mM). Sample absorbance 0.3317 Slope of the calibration line: 5.22

Answer 1

Concentration of phosphate = 635.4 mM

Step-by-step explanation:

Given Data;

Volume of soft drink = 10.00 ml

Diluted volume = 100.00 ml

Sample absorbance = 0.3317

Slope of the calibration line = 5.22

In calculating the concentration of phosphate in the drink, we use the formula;

Absorbance = slope * concentration

Making concentration subject formula and substituting, we have;

Concentration = Absorbance/slope

= 0.3317/5.22

= 0.06354 M ( concentration of the sample)

When is has been treated with acid and diluted to 100.00ml, the concentration of phosphate becomes;

concentration of phosphate = 0.0635 * 100/10

= 0.0635 * 10

= 0.635M

= 635.4 mM