Determination of the concentration of Zn(II) in a sample of river water was carried out by the standard addition method. A standard solution of 20 ppm Zn(II) was prepared and added to the filtered river water sample. The prepared series of solutions were then measured for absorbance with AAS and the results were as follows: 1. Fe(lII) 20 ppm (ml) | Sample (ml) 0,0 H2O (ml) A 0.111 1 9. 0,2 1 8 0.167 0,4 1 7 0.223 0,6 1 6 0.286 0,8 1,0 1 5 0.347 1 4 0.401 a. Draw a calibration curve for the volume of Zn(1I) vs. absorbance and concentration i Zn(11) vs. absorbance b. Based on the available data, what is the concentration of Zn(lI) in the sample

Determination of the concentration of Zn(II) in a sample of river water was carried out by the standard addition method. A standard solution of 20 ppm Zn(II) was prepared and added to the filtered river water sample. The prepared series of solutions were then measured for absorbance with AAS and the results were as follows: 1. Fe(lII) 20 ppm (ml) | Sample (ml) 0,0 H2O (ml) A 0.111 1 9. 0,2 1 8 0.167 0,4 1 7 0.223 0,6 1 6 0.286 0,8 1,0 1 5 0.347 1 4 0.401 a. Draw a calibration curve for the volume of Zn(1I) vs. absorbance and concentration i Zn(11) vs. absorbance b. Based on the available data, what is the concentration of Zn(lI) in the sample

Chemistry & Chemical Reactivity

10th Edition

ISBN:9781337399074

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter4: Stoichiometry: Quantitative Information About Chemical Reactions

Section4.9: Spectrophotometry

Problem 2.1ACP: Excess KI is added to a 100.0-mL sample of a soft drink that had been contaminated with bleach,...

See similar textbooks

Similar questions

The phosphate in a 3.000 g sample of industrial detergent was precipitated by the addition of 1.000 g of AgNO3. The solution was filtered and the filtrate required 18.23 mL of 0.1377 M KSCN for titration to the FeSCN2+ end point. Calculate the percentage of phosphate in the detergent.
Fe+3 (aq) + SCN – (aq) FeSCN +2 (aq) She mixes 4.00 mL of 2.00 mM SCN– and 5.00 mL of 2.00 mM Fe+3 ions, then diluting with 1.00mL of water to give a total volume of 10.00mL. She measures the absorbance of the solution asbeing 0.210. If she has previously calculated the molar absorbtivity constant (ε) of the product tobe 2583 cm–1 M–1, what is her best estimate for the K value for this reaction?
An EDTA solution was prepared by dissolving approximately 3 grams of Na2H2Y•H2O in sufficient water to give 1 liter of solution. This solution was then standardized against 50.00 mL aliquots of 0.004517 molar Mg2+. An average titration volume of 32.22 mL was required. Determine the molar concentration of EDTA.
For complexometric titration of Ca (II) ions in the shell of an egg sample weighing 59,427 g, the necessary processes were applied to the egg shells and a sample of 100 mL was prepared. From the prepared sample, 1 mL was taken and diluted to 100 mL, the pH was adjusted, and two drops of EBT indicator were dripped on it. The prepared solution was titrated with 27.4 mL of EDTA solution set at 0.0097 M. Calculate the amount of calcium in the sample in CaCO3%. (Ca = 40g / mol, CaCO3= 100g / mol)
A 20 ml aliquot of drinking water containing Fe(II) and Fe (III) is treated with hydroquinone to reduce all dissolved iron to Fe(II),0- phenanthroline is added and the aliquot is diluted to 50 ml and the absorbance in a 2.00 cm cell is 0.085 at 510 nm. Calculate the iron content of the water as ppm? ε = 1.11 x104 L/mol cm
The un-ionized form of the weak acid HA does not absorb in the visible region. When it ionizes, its conjugate base (A-) absorbs light strongly at 510 nm. The following data were obtained by measuring the absorbance at 510 nm of solutions with a concen- tration of 1.0 x 104 M HA in different pH buffers. pH Absorbance 2.0 0.00 3.0 0.00 4.0 0.00 5.0 0.025 6.0 0.180 7.0 0.480 8.0 0.570 9.0 0.595 10.0 0.595 11.0 0.595 12.0 0.595 What is the approximate pK of HA?
A 0.7120 g of iron ore was brought into solution and passed through a Jones reductor. Titration of Fe(II) produced required 39.21mL of 0.02086M KMnO4. Express the results of analysis in terms of (a) percent Fe (MM 55.85) and (b) percent Fe2O3 (Molar mass= 159.69). 5Fe+2 + MnO4- +8H+ → 5Fe+3 + Mn+2 + 4H2O
Janine's research focuses on the ability of quercetin, a flavonoid and natural dye, to detect the presence of Co2+ in wastewater samples. She prepared a set of calibration standard solutions by adding an excess of quercetin to solutions of varying Co2+ concentration and maintaining it at pH 6.4 using a Tris-HCl buffer. The reaction yields a colored complex solution that has a maximum absorbance at 440 nm:Co2+ + 2 Quercetin --> Co(Quercetin)22+ The absorbance measurements for the calibration solutions prepared are shown in the tables; a cuvette with a 2.50 cm path length was used. [Co2+], in M Absorbance Color Wavelength range (nm) 0.05 0.100 Red 625-740 0.10 0.166 Orange 590-625 0.20 0.285 Yellow 565-590 0.30 0.367 Green 490-565 0.40 0.454 Blue 440-490 0.50 0.571 Violet 380-440 Part of her research is to determine the extent of Co2+ pollution in a stream near a pharmaceutical company. She obtained a 50.0-mL sample of the stream water and buffered it to pH 6.4. She…
(b) An unknown solution containing 25.00 mL of Ni2+ in dilute HCI is treated with a known excess of 25.00 mL of 0.05382 M EDTA solution. The solution turns yellow when a few drops of indicator are added. The excess unreacted EDTA back titrated with 0.02299 M Zn²*, which requires 17.00 mL to reach the red end point. What is the molarity of Ni2+ in the unknown solution?
Treatment of ammonia with phenol in the presence of hypochlorite yields indophenol, a blue product that absrobs light at 625 nm, which çan be used for the spectrophotometric determination of ammonia. gan OCF OH + NH3 indophenol anion To determinè the ammonia concentration in a sample of lake water, three samples are prepared. In sample A, 10.0 mL of lake water is mixed with 5 mL of phenol solution and 2 mL of sodium hypochlorite solution, and diluted to 25.0 mL in a volumetric flask. In sample B, 10.0 mL of lake water is mixed with 5 mL of phenol solution, 2 mL of sodium hypochlorite solution, and 2.50 mL of a 5.50 x 10-4 M ammonia solution, and diluted to 25.0 mL. Sample C is a reagent blank. It contains 10.0 mL of distilled water, 5 mL of phenol solution, and 2 mL of sodium hypochlorite solution, diluted to 25.0 mL. The absorbance of the three samples is then measured at 625 nm in a 1.00 cm cuvette. The results are shown in the table. Sample Absorbance (625 nm) A 0.361 B 0.608 C…
A cyanide solution with a volume of 10.33 mL was treated with 22.00 mL of Ni2+ solution (containing excess Ni2+) to convert the cyanide into tetracyanonickelate(II): 4CN−+Ni2+⟶Ni(CN)(2−)/4 The excess Ni2+ was then titrated with 11.85 mL of 0.01303 M ethylenediaminetetraacetic acid (EDTA): Ni2++EDTA4−⟶Ni(EDTA)2− Ni(CN)(2−)/4 does not react with EDTA. If 38.80 mL of EDTA were required to react with 30.47 mL of the original Ni2+ solution, calculate the molarity of CN− in the 10.33 mL cyanide sample. [CN-] = ________________________________M
1. A 0.7120 g of iron ore was brought into solution and passed through a Jones reductor. Titration of Fe(II) produced required 39.21mL of 0.02086M KMnO4. Express the results of analysis in terms of (a) percent Fe (MM 55.85) and (b) percent Fe₂O3 (MM 159.69). 5Fe +2 + MnO4 +8H+ → 5Fe+³+ Mn+² + 4H₂O