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 = 1.585x + 0.041 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 27.00 mL. If the absorbance of the dilute Kool-aid sample at the appropriate wavelength for their assigned dye is 0.931, 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.

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?

I need help. Using a standard curve: Another student produced the standard curve shown here ( Fig.2.2) which shows the linear relationship between absorbance and Cu2+ concentration. They then measured the absorbance of their unknown solution to be 0.48126 AU. Use their trendline equation to calculate the concentration (M) of Cu + in their Unknown Solution. Show your work and consider sig figs.

After determining the absorbance of several standards of known concentration, the trend line for a calibration curve plotting absorbance (y-axis) against concentration (uM, x-axis) is determined to be y=4.244x+0.0000. The absorbance of a solution of unknown concentration is determined to be 0.604. Calculate the concentration of the unknown solution in microM. Give answer to 3 decimal places

A student prepared four standard solutions of (NH4)2Fe(SO4)2 and measured their absorbance at 505 nm.  She created a calibration plot with the best-fit line of y = 9372 x + 0.0539.  She measured the absorbance of her diluted unknown sample solution as (4.69x10^-1) nm.  If she prepared her diluted sample solution by diluting 10.00 mL of the original solution to a total volume of 50.00 mL with deionized water, what is the concentration of Fe2+ in her original solution?  Answer in units of M. Note: Your answer is assumed to be reduced to the highest power possible.

if its absorbance is 0.900,  find the molar absorptivity of a solution containing 3.0 x 10-3 g/L solute (MW=180) in a 4.0 cm cell

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) = %

A solution with %T = 75.9% has an absorbance equal to: A = log (1 T) T= (% T 100)

If the absorbance of one of the buffer solutions was 0.123 and the absorbance of the basic solution was 0.687, what is the value for the [X²]/[HX] ratio? Report your answer with 3 decimal places. Your Answer: Answer