Question

Suppose that you are using the AAS to determine the concentration of Ca in Minute Maid Orange Juice whose label states that its Ca content is 300mg/240ml serving. What sample amount would you take in order to prepare a 100ml solution whose Ca concentration is 50ppm (which is the middle of the AAS linear range for Ca ). (Atomic weight of Ca=40.08 g/mole )

A) 1.25ml
B) 4.0ml
C) 6.25ml
D) 40ml
E) none of the above

Answer 1

To prepare a 100ml solution with a Ca concentration of 50ppm, you would need a sample amount of 3.121ml.

Step-by-step explanation:

To determine the sample amount needed to prepare a 100ml solution with a Ca concentration of 50ppm, we can use the formula:

Concentration = (mass of solute / volume of solution) * 1000000

Given that the Ca content in Minute Maid Orange Juice is 300mg/240ml serving, we can calculate the mass of Ca in 100ml serving:

Mass of Ca = (300mg/240ml) * 100ml = 125mg

Using the molar mass of Ca (40.08 g/mol), we can calculate the sample amount:

Sample Amount = (125mg / 40.08g/mol) * 1000ml/L = 3.121ml

Therefore, the correct answer is (E) none of the above.