Question

show calculations please

3. A standard solution of Fe(II) [10.0 ppm) was prepared, the appropriate reagents were added, and a series of standard solutions were prepared and the transmittance of the solutions were read out as follows: Vol. of std solution (ml) Final vol. (mL) %T 0.00 100.0 100.0 5.00 100.0 77.7 25.00 100.0 30.2 50.00 100.0 10.4 (a) (3 pts) plot a calibration curve and find out the slope and y-intercept for the linearly related Absorbance with concentration. (b) (4 pts) An unknown solid was prepared by dissolving 0.1014 g of the iron(II) containing compound and diluting the resultant solution to 500.0 mL. A 15.00 mL aliquot of this solution was obtained, treated appropriately, and diluted to 100.0 mL. This final solution was then determined to have 51.7%T. Calculate the percent iron in the unknown solid. me 96072012 8994....jpg 95662192 6508....jpg 96233419 28

Answer 1

Plot: Absorbance vs Concentration Absorbance Cs Seanned with Concentration (ppm) CamScanner

NEW Solution: -3- Concentration of standard solution Calculation Concentration of stock standard solution - 100 ppm Volume of standard Solution taken=5.ooml 5oomul 500 ml 500054 Volume of firal solution = loome = lromexil osome 012 SO v V2 where, C SV are the concentration & 10.0 PP mxo.oosL=C₂X0tL and volume of stock solution. G. O'oppmXOO05L 1. CXV are the concentrations OIL and volume of diluted solution e C2 = 0.5ppm Similarly for other solution 0 A= 2-log To A = 2- 10g 100% A=2- 2 @ A=2-1097% A = 2 - log 77.7% A = 2-1.89 Scanned, with AmsCahher

Absorbance 00 100.0 similar calculation for other solution. Tvolume of Std Final volumec mes y concentration S.Nbsolution CmL) 100 0.00 0:00 100.0 177.7 0.5 3. 25.00 100.0 30.2 12.5 9 50.00 100.0 104 5 .00 OU 12.15.00 0.52 0.98 - a) from the graph equiation of lene : Y=0.1958.4 +0.0109, R2=0.999 -ujj 13 Ece ü) comparing the equation is with (ii) Yo Absorbance (A) 2-concentration (C) Sot Slope = Eli So, from this line equation Slope - 0.1958 tot ppm I am mtercept = 0.009. Saub b) 7,= 51.7.10 Astro 2-log T'%. CS Scanned Aith 2-109 517 CamScherd-.79

A=0:29 A= E axil C= A Šī c= 0. 29 0.1958 ppm e = 1.48 ppm. Concentration of prepared loomi Fe (II) = 1.48PPm. volume of stock solution= 15.0ome = 0.0156 by applying where, er, a CzV₂ C, & Va are the concent 0.1LX1:48 PPm= 0.015LXlZ - tration and volume of diluted solution s C OILX 48 ppm Cat V are the concent & 0.01SL -sation & Volume of a stock G2 = 9.874 ppm solution. Again, this solution token from 500m2 solution. so, volume of solution = 15ml -0.0151 CS Scanned concentration of solution a 9.874 ppm, CamScanner

2 2 2 volume of stock solution = 500m2 = 0 5L concentration of unknown solution = 9.874 ppm = 9.874 mg k Mass- of Fe (II) in Unknown sample= ppmx Volu - 9.844 mg x 0.52 Volume 24-937 ng mass of fe cII) in Unknown sample=4937ng = 4.937 mg x lg - Toroong = 0.004937 9 So, Mars of re CI) Unknown sample= 0.10149 A Mass of Fe (II) in Unknown sample=0.0089379 = % Fe (II) = mass of Fe (II) x 10 Mass of Unknown 0-004937 g ximo 24.86%. Gs Scanned with 0.10144 le (Baineanknown comple was = 4.86%.