Sally obtains a standard calibration curve for their assigned food dye by plotting absorbance versus concentration (in M) of known solutions and finds the following slope and intercept: y = 1.667x + 0.003 Sally finds that her original Kool-aid sample is too concentrated, so they dilute it by transferring 4.00 mL of the original Kool-aid sample into a new container and diluting to a total volume of 47.00 mL. If the absorbance of the dilute Kool-aid sample at the appropriate wavelength for their assigned dye is 0.457, determine the concentration (in M) of the assigned food dye in the original Kool-aid sample. Report your answer with three places after the decimal.

Based on the picture i) the sensitivity of method. ii) the concentration of lead in the soil in mg/kg.

Sally obtains a standard calibration curve for their assigned food dye by plotting absorbance versus concentration (in M) of known solutions and finds the following slope and intercept: y = 1.646x + 0.026 Sally finds that her original Kool-aid sample is too concentrated, so they dilute it by transferring 13.00 mL of the original Kool-aid sample into a new container and diluting to a total volume of 37.00 mL. If the absorbance of the dilute Kool-aid sample at the appropriate wavelength for their assigned dye is 0.950, determine the concentration (in M) of the assigned food dye in the original Kool-aid sample. Report answer with three places after the decimal.

3. An indicator is a dye whose spectrum changes with pH. Consider the following data for the absorption spectrum of an indicator (pK = 4) in its ionized and nonionized form. InH+ → In + H* Molar absorptivity, ɛ (M1.cm1) InH+ (nm) In 400 10,000 420 15,000 2,000 440 8,000 8,000 460 12,000 480 3,000 The absorbance of the indicator solution is increased in a 1-cm cell and found to be 400 420 440 460 480 (nm) A 0.250 0.425 0.400 0.300 0.075 a. Calculate the pH of the solution. [4.0] b. Calculate the absorbance of the solution at 440 nm and pH 6.37 for the same total indicator concentration. [0.400] c. If you want to measure the quantum yield of fluorescence of In and H* independently, what wavelength would you choose for exciting In H+? For exciting In? Why?