Food Dyes Analysis of Commercial Products Part 2 (1)

Determine the final concentration in mol dm–3 of K+ and SO42– when the following three solutions in volumetric flasks are mixed together: 500 cm3 of 0.20 mol dm–3 KAl(SO4) 2; 1000 cm3 of 0.050 mol dm–3 K2SO4 and 500 cm3 of water. The concentration of K+ is       Select one: a. 0.20 × 103 mol dm–3 b. 0.20 mol dm–3 c. 0.10 × 10–3 mol dm–3 d. 0.10 mol dm–3

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The luminescent first-order decay of a certain organic molecule yields the following data t/s 2 3 4 10 I 100 60.65 36.79 22.31 13.53 8.21 0.67 where I is the relative intensity. Calculate the mean lifetime T for the process. 8.57 X S Is it fluorescence or phosphorescence? O fluorescence O phosphorescence

In order to measure riboflavin in a breakfast cereal, a 5.00-gram sample of the cereal was extracted with acetic acid and filtered. The extract was transferred to a 50.0 mL volumetric flask and diluted to the mark. The sample was transferred to a cuvette and the fluorescence was measured. The instrument read 59 units (Fluorescence units –an arbitrary scale). 24.00 mL of the cereal extract was sample was mixed with 1.0 mL of a riboflavin standard that was 0.500 ug/mL. The fluorescence of this mixture was measured and read 94 fluorescence units. Calculate the concentration of riboflavin per gram of cereal (use µg/gram of cereal).

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Calculate the molar extinction coefficient (e) of a molecule at a particular wavelength given that a 0.000764 M solution of the molecule produced a fluorescence intensity (I) of 1177 when the irradiance of the beam incident to the sample (Po) was 821 and the length of the medium (b) was 1.12 cm. The proportionality constant k' for this molecule is 0.319. € = ×10 TOOLS M-1.cm-1

What is the total molar concentration of all the ions in 0.0150 Msolutions of the following salts in water?

It is found that up to 0.0110 g of SrF2 dissolves in 100 mL of aqueous solution at a certain temperature. Determine the value of Ksp for SRF2. 1 2 NEXT > Based on the given values, fill in the ICE table to determine concentrations of all reactants and products. SFF2(s) Sr**(aq) 2 F (aq) + Initial (M) Change (M) Equilibrium (M) 5 RESET 0.0110 8.76 x 10-5 8.76 x 10-4 1.75 x 10-4 1.75 x 103 -0.0110 -8.76 x 10-5 -8.76 x 10-4 -1.75 x 10-4 -1.75 x 103 +x +2x -2х -X 8.76 x 10-5 + x 8.76 x 10-5 1.75 x 10-4 + 2x 1.75 x 10-4 - 2x

When opening the cover of an analytical detector, which optical elements can help us to differentiate whether the instrument is a spectrofluorometer or a UV-Vis spectrophotometer. Justify your answer:

Laser. Indicate the relationship between metastable state and stimulated emission.

What is the actual or real-life application of electrogravimetric analysis? Include the specific methodology.

True or false. Why?

Flame Atomic Absorption Spectroscopy (FAAS) method is selected due to its wide applicability for metal ion analysis in drinking water samples. Provide appropriate discussion to determine the concentration of selected heavy metals (Cu and Cr) in the unknown tap water sample.

An atomic absorption method for the determination of the amount of iron present in used jet engine oil was found from pooling 30 triplicate analyses to have a standard deviation s = 3.6 mg Fe/mL. If s is a good estimate of σ, calculate the 95 and 99% confidence intervals for the result 18.5 mg Fe/mL if it was based on (a) a single analysis, (b) the mean of two analyses, and (c) the mean of four analyses.

An article in Solid State Technology, "Orthogonal Design of Process Optimization and Its Application to Plasma Etching" by G.Z. Yin and D.W. Jillie (May, 1987) describes an experiment to determine the effect of C2F6 flow rate on the uniformity of the etch on a silicon wafer used in integrated circuit manufacturing.  Data for two flow rates are as follows: C2F6 Uniformity Observation (SCCM) 1 2 3 4 5 6 125 2.7 4.6 2.6 3.0 3.2 3.8 200 4.6 3.4 2.9 3.5 4.1 5.1 C2F6 Uniformity Observation (SCCM) 1 2 3 4 5 6 125 2.7 4.6 2.6 3.0 3.2 3.8 200 4.6 3.4 2.9 3.5 4.1 5.1 (a)  Does the C2F6 flow rate affect average etch uniformity?  Use = 0.05. (b)  What is the P-value for the test in part (a)?

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