Question

Table 1: Components of Solutions (Target Values) that will be used in this Spectrophotometer Experiment mL ml NH2OH.HCI mL phen Fe2+ mL NHAC 5 5 10 Flask Number/Type 1./BLANK 2. /STANDARD 3./STANDARD 4. /STANDARD 5. /STANDARD 6./UNKNOWN 10 10 0.0 1.00 2.00 4.00 8.00 UNKNOWN 10 10

Question 1

Referring to Table 1 on page 9, what is the final concentration of Fe⁺² in ppm of the last standard solution assuming that you used exactly the target value of 8.00 ml Fe⁺² in the 100 mL flask? For this question, assume that you added exactly the volumes of all reagents as listed in the table. (Remember that the stock solution concentration is 50.00 ppm.)  Show all your work carefully using good form and significant figures.

Answer 1

we luxe Mini= M2 V₂ mi and my are initial and final concentrations of solution rexpectively. Vi, and U2 are initial and Final volumes of Solieron renpectively MI: SO rom (Stock Solution ) M2 = v =8 ? m Coiluted solution (stock solution V₂ = 100 mL Coiluted volume) 50 ppm x 8 m2 = M2 x 100 m2 m₂ = 50 ppm x 8 mL 100 mL m2 = so ppm x 8m 100 mark = 400 rpm 100 = 4 ppm 2. conc. of Fe2+ in last standard solution is a pom