The following results were obtained when each of a series of standard silver solutions was analyzed by flame-atomic absorption spectrometry: Concentration (ng-mL¹) Absorbance (r.u.) 0 5 10 15 20 25 30 40 0.003 0.127 0.251 0.390 0.498 0.625 0.763 0.771 Determine the slope and intercept of the calibration plot, along with their confidence limits (95%). Using the data from exercise 1 above, estimate the confidence limits for the silver concentration in: a) A sample giving an absorbance of 0.456 in a single determination. b) A sample giving absorbance values of 0.308, 0.317, 0.347, and 0.412 in four separate determinations.

0.1040 g of a solid sample containing copper was dissolved by acid and transferred to a 250.00 mL volumetric flask and volume was made up with distilled water. The solution was then diluted by a factor of 20. The final solution was analyzed by atomic absorption spectrophotometry and the concentration was found be 3.109 ppm, What is the weight percentage of copper in the original solid sample? Keep four significant figures in your final answer. Do not try to include the "%" in your answer. e.g. if your final answer is 10.01%, only write 10.01 in the box.

Please answer all required.

An unknown sample of Yellow 6 solution has the absorbance equal to 0.96. The slope of the Beer's law calibration plot constructed using a 3.8E-5M stock solution of Yellow 6 is 0.0117 (%) 1. What is the molar concentration of the unknown sample (in mole L-¹)? Please give your answer to 3 significant figures (1 additional SF is used to minimize rounding errors). M Hint

Determining the concentration of unknown solution using uv-vis spectroscopy. The absorbance vs concentration has an equation of straight line of y=8.4052x+0.0002 with r2=1. The unknown solution's absorbance is 0.150. From 75 mL sample, A 15 mL aliquot was examined. The 15 mL aliquot was mixed with 15 mL 1% percent by mass over volume HCl and was diluted to 40 mL with water. What is the concentration of the solution in the 75 mL sample?

A company is producing a powder which can be reconstituted as a healthy drink for the elderly. Analysis of the powder for calcium involved using the following procedure. 4 g of powder was reconstituted to 150 ml with water. Thirty ml of 24 % TCA was added to 30 ml of this solution. The mixture was allowed to stand for 15 mins and then filtered. The filtrate was analysed for calcium using atomic absorption spectroscopy. From the standard curve it was found that the reading for the analysed sample was 24mg/litre. Calculate the concentration of calcium in the powder (mg/kg).

A calibration curve is made for the absorbance as a function of concentration of blue dye (in mg/L).  The slope of the curve is 0.131; the y-intercept is -0.01869; the correlation is 0.993.  If a consumer sample has an absorbance of 0.120 on the same instrument, what is its concentration of blue dye, in mg/L? a. 0.034 b. 0.935 c. 0.993 d. 1.06

0.1120 g of a solid sample containing copper was dissolved by acid and transferred to a 250.00 mL volumetric flask and volume was made up with distilled water.  The solution was then diluted by a factor of 25.  The final solution was analyzed by atomic absorption spectrophotometry and the concentration was found be 2.982 ppm, What is the weight percentage of copper in the original solid sample?  Keep four significant figures in your final answer.

Exactly 5.00 mL aliquots of a solution containing analyte X were transferred into 50.00-mL volumetric flasks and the pH of the solution is adjusted to 9.0. The following volumes of a standard solution containing 2.00 µg/mL of X were then added into each flask and the mixture was diluted to volume: 0.000, 0.500, 1.00, 1.50 and 2.00 mL. The fluorescence of each of these solutions was measured with a fluorometer, and the following values were obtained: 3.26, 4.80, 6.42, 8.02 and 9.56, respectively. ii. Using relevant functions in Excel, derive a least-squares equation for the data, and use the parameters of this equation to find the concentration of the phenobarbital in the unknown solution.

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.