Show all work: What is the equation of the line? How does Beer\'s Law resemble a
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What is the equation of the line? How does Beer's Law resemble a linear equation? What is spectrophotometry? What is the wavelength range for the visible region of the spectrum? What does Beer's Law measure? What is molar absorptive? How will its magnitude affect the detection limits of a substance in a solution? What does a maximum in a graph of Absorbance vs. wavelength mean? A solution is prepared by transferring 8.756 grams of cobalt (II) chloride hexahydrate to a 250 mL volumetric flask. What is the molarity of the solution? 18.00 mL of the above solution is diluted to 30.00 mL with deionized water; what is the molarity of the new solution? Use the graph to answer questions below: What is the molar absorptivity of cobalt chloride? What is the concentration of cobalt in a solution with an absorbance of 0.050 M?Explanation / Answer
1) equation of line is y = mx + c , beers law is A = eCl where el is slope . Thus beers law show a straight line.
2) spectrophotometry is quantitative measurement of refelction or transimission of material as function of wavelength.
3) visible rangle is 400nm -700nm ( nm = nanometers = 10^-9m)
4) Beers law measures absorbance of material.
5) Molar absorbitivity is absorbance that occurs when conc = 1 mol/cc and when lenght of cell = 1 cm .This is a constant for species and its magnitude shows how strongly does a species absrobs light at given wavelength.
6)The maximum is denoted by lamda max. Its gives information about electronic environment and structure of chemical compound used.
7) 8.576 gm CoCl2 = 8.576/238 =0.036 moles , vol = 250 ml = 0.25 L
Molairity = moles/vol = (0.036/0.25) =0.144
8) V1 = 18 , V2 = 30
M1V1 = M2V2 , 0.144 x 18 = M2 x 30 , M2 = 0.0865 is new molariyt
9) molar absorbtivity = slope = (y2-y1)/(x2-x1) = (0.5-0.36)/(0.105-0.075) = 4.67 M-1cm-1
10) A = 0.05 = eCl ( l = 1 when not mentioned)
0.05 = 4.67 x C
C = 0.0107 M