Blue Blue dye stock solution Absorbance at 630 nm Calibration curve A solution is prepared by diluting 2.79 mL of the blue dye stock solution to 25.00 mL. The measured absorbance for the prepared solution is listed in the data table. (a) What is the theoretical molar concentration? [Bluel theoretical (b) What is the experimental molar concentration? = 0.293 M 0.00265 y = 0.0833x x 10 [Bluel experimental (c) What is the percent error? Percent error (blue) = x 10 % M M

Blue Blue dye stock solution Absorbance at 630 nm Calibration curve A solution is prepared by diluting 2.79 mL of the blue dye stock solution to 25.00 mL. The measured absorbance for the prepared solution is listed in the data table. (a) What is the theoretical molar concentration? [Bluel theoretical (b) What is the experimental molar concentration? = 0.293 M 0.00265 y = 0.0833x x 10 [Bluel experimental (c) What is the percent error? Percent error (blue) = x 10 % M M

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter7: Statistical Data Treatment And Evaluation

Section: Chapter Questions

Problem 7.10QAP

See similar textbooks

Similar questions

Blue Blue dye stock solution 0.293 M Absorbance at 630 nm 0.00265 Calibration curve y = 0.0833x A solution is prepared by diluting 2.81 mL of the blue dye stock solution to 25.00 mL. The measure absorbance for the prepared solution is listed in the data table. (a) What is the theoretical molar concentration? [Blue]theoretical | × 10 |M (b) What is the experimental molar concentration? [Bluelexperimental x 10 M (c) What is the percent error? Percent error (blue) =
4. The molar absorptivities of the indicator weak acid HIn (K₁ = 1.42 x 105) and its conjugate base In at 570 were determined as ε(HIn) = 7120 and ɛ(In) = 961. The optical length b = 1.00 cm. (a) What is the absorbance of an unbuffered indicator solution having total indicator concentration 8.0 × 10%. (b) What is the absorbance of a buffered indicator solution having total indicator concentration 8.0 x 105 and pH = 6.5.
5. (1) (ii) Ibuprofen (206.3 g/mol) absorbs at 255 nm and shows a molar absorptivity of 3010 L/mol.cm. A tablet of ibuprofen, 0.6654 g, was ground and 0.2203 g powder was dissolved in 20% methanol in a 100 mL volumetric flask (Solution A). Exactly 5.0 mL of Solution A was diluted in a 50.0 mL flask and the resulting solution showed an absorbance of 0.1228 AU in a 1.00 cm cell. (i) What is the concentration (mol/L) of ibuprofen in the 100 mL stock solution? (ii) Report the amount of ibuprofen in mg/Tablet. Ibuprofen H3C | HCCH; 1 H3C CH3 -CH-COOH
6. Blue Blue dye stock solution 0.293 M Absorbance at 630 nm 0.00265 Calibration curve y = 0.0833x A solution is prepared by diluting 2.79 mL of the blue dye stock solution to 25.00 mL. The measured absorbance for the prepared solution is listed in the data table. (a) What is the theoretical molar concentration? [Blue]theoretical x 10 |M (b) What is the experimental molar concentration? [Blue]experimental x 10 M (c) What is the percent error? Percent error (blue) = %
(b) Using appropriate chemical reactions for illustration, show how calcium present as the dissolved HCO3- salt in water is easier to remove than other forms of hardness, such as dissolved CaCl2. (c) A water has the following analysis: mg/l mg/l Na+ - 20 Cl- - 40 K+ - 30 HCO3- - 67 Ca2+ - 5 CO32- - 0 Mg2+ - 10 SO42- - 5 Sr2+ -2 NO3- - 10 What is the total hardness, carbonate hardness and noncarbonated hardness in mg/l as CaCO3.
(5) A standard sclution of hydrated iron(II) sulphate, FeSO,.XH20, was preparcd by dissolving 5.8 g of the salt in a volumetric flask and making it up to 250 mL (250 cm³). Twenty-five millilitres (25 mL (25 cm³)) of this solution was acidified and found to react exactly with, 22.8 cm³ (22.8 mL), of 0.018 M potassium 3 permanganate solution. The half-equations for the reaction are: JAS 00 MAC aJTT MNO4 (aq) + 8H*(aq) Fe*(aq) + Mn2“(aq) + 4H20(1) → Fe*(aq) + e MOTTAMIMAXE 2+ (i; What is the indicator for the titration of a solution of iron (II) sulphate and potassium permanganate soluticn? (ii) Indicate the colour at the end point if the permanganate is in the burette. blood ofieido rosd sl (iii) Why is it necessary to acidify the iron(II) solution before titration? o sd am eorsiuols
Solutions of cobalt (II) ions have a magenta color with a molar absorptivity constant (e) value at 511 nm of 5.87 M-1cm-1. A 0.500 mL sample is transferred from a 50.0 mL stock solution of Co(NO3)2 and diluted with water to a final volume of 7.50 mL. The dilution had an absorbance value at 511 nm in a standard cuvette (1.00 cm light path) of 0.382. Calculate the mass of Co(NO3)2 contained in the original 50.0 mL stock solution.
Define the following terms:(i) Adsorption(ii) Peptization(iii) Sol
2. Answer ALL parts. (a) The absorbance of compound A was measured in a 1.00 cm cuvette at 238 nm. A 3.96 x 10 M solution of compound A exhibited an absorbance of 0.624. A blank solution containing only the solvent had an absorbance of 0.029 at the same wavelength. Calculate the molar absorptivity of compoundA in m' mole". (i) The absorbance of an unknown solution of Compound A in the same solvent and cuvette was 0.375 at 238 nm. Find the concentration of A in the unknown. (iii) A concentrated solution of Compound A in the same solvent was diluted from an initial volume of 2.00ml to a final volume of 25 ml and then had an absorbance of 0.733 under the same conditions. What is the concentration of A in the concentrated solution? (iv) What type of cuvette was used in the above analysis? Justify your answer. (b) Name ONE advantage and ONE disadvantage of a linear photodiode array detector compared to a traditional photomultiplier based spectrometer. (c) Why is an FTIR spectrum digital in…
One of the CHEM3341 student Ms. Fatima Al Wahaibi wanted to analyse phosphate ion concentration in Fertilizer industry wastewater sample collected from Rusayl Industrial Estate using spectrophotometer method. She mixed 200.00 mL of wastewater sample which contains only Na;PO, (unknown molarity) with 400.00 mL of 0.0200 M K,PO4 in a one liter beaker to make a Solution A. She then transferred 25.00 mL of Solution A to a 250.00 mL volumetric flask and added distilled water up to the calibration mark to make up Solution B. The Concentration of phosphate ions in Solution B is known to contain 3.00 x 103 mol/L from the spectrophotometric analysis at 460 nm using 1 cm cuvette. Calculate the concentration of phosphate ion in wastewater and how many phosphate ions are present in this wastewater.
In the determination of iron in fortified cereals by atomic absorption, 0.9133 g of sample was weighed. After a previous treatment, it was dissolved and diluted to 100 mL, an aliquot of 25.0 mL was taken, this was diluted to 100 mL and this solution presented an absorbance reading of 0.251. A series of iron standards of the following concentrations were prepared: 0.0; 1.0; 2.0; 2.5 and 3.0 ppm. Whose absorbances were 0.0; 0.241; 0.405; 0.520 and 0.640. Determine the iron concentration in mg/100 g of sample.
A molecular exclusion column has a diameter of 7.8 mm and a length of 30 cm. The solid portion of the particles occupies 20% of the volume, the pores occupy 40%, and the volume between particles occupies 40%. (a) At what volume would totally excluded molecules be expected to emerge? (b) At what volume would the smallest molecules be expected? (c) A mixture of polymers of various molecular masses is eluted between 23 and 27 mL. What does this imply about the retention mechanism for these solutes on the column?