1. Questions

Chemistry

Indicate how each of the following would affect the value of the absorbance (too high, too low, or not effect) of the indicated solution.
I really need help. I do not understand these questions!
This is from a chemistry activity to determine the unknown concentration of an Erythrosin B solution by using a spectrophotometer.

a. A student prepares solution A as instructed and pours it into a wet beaker.

b. A student rinses the 10.00 mL pipet only with DI water in the preparation of D (but does the rest of the procedure as instructed).

c. A student fills the volumetric flask containing solution B so that the bottom of the meniscus is below the mark on the flask (but does the rest of the procedure as instructed).

  1. 👍
  2. 👎
  3. 👁
Sharon

  1. You haven't provided a clear set up but here is my best guess. I will put a proviso on each.
    a. IF you are talking about the absorbance of soln A after it has been poured into a wet beaker, the absorbance will be less BECAUSE the solution has been diluted (with the water in the wet beaker).

    b. Here it isn't clear what absorbance on what solution we're talking about but the solution of D will be weaker than your calculations show because the pipet delivered some sample diluted with water that was already in the pipet. With this information you should be able to take this weaker solution and follow through to the appropriate answer.

    c. Again it isn't clear how solution B figures into the rest of the problem but you know that the sample in the volumetric flask will be more concentrated than calculations show it to be because less water was added to the volumetric flask.

    1. 👍
    2. 👎
    DrBob222

Respond to this Question

First Name

Your Response

Similar Questions

  1. science

    1. Do excessively high temperatures cause people to behave immorally? 2. What is the function of spines on cacti? 3. What is the sequence of the human genome? 4. Does salt negatively affect the rate of radish seed germination? 5.

  2. Chemistry

    You are measuring the concentration of Fe2 in a sample by measuring the absorbance of its complex with ferroxine. Your sample, measured in a 1.00-cm pathlength cuvette, has an absorbance of 0.347 while the reagent blank in the

  3. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN–

  4. chemistry

    The following errors occurred when the above experiment was carried out. How would each affect the calculated molecular mass of the solute (too high,too low, no effect)? Explain your answer. (a) The thermometer uses actually read

  1. chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN–

  2. College Chemistry Lab

    Suppose that a 2.50x10^-6M solution of red dye No. 2 had an absorbance of 0.585 at its wavelength of maximum absorbance. A second solution of red dye No. 2 is too concentrated to read its absorbance so 5.00 mL of the concentrated

  3. Chemistry

    A metal element (M) forms a hexadentate complex with the ligand ethylenediammine (en). Its formula is M(en)32+. The metal ion and the ligand do not absorb in the visible region of spectrophotometer and a 1.00 cm cuvette, the

  4. Chemistry

    The regression line from a plot of absorbance vs. concentration yields: 𝐴 = 2.31[𝐶] + 0.002. If the absorbance of an unknown is measured to be 0.124, what is the concentration of the analyte [𝐶]?

  1. Chemistry

    The spectrophometer was used to measure the absorbance of each of a series of [FeSa]+ solutions. A standard curve was construnceted by plotting the absorbance vs. concentration (M). The slope and y-intercept were found to be 1496

  2. Science

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN–

  3. english

    Can someone please check my homework for me? · Write two paragraphs about how interest rates affect our purchasing decisions. · Identify the topic sentence in each by underlining it. · Post your paper as an attachment. Interest

  4. Chemistry

    The rate of a first-order reaction is followed by spectroscopy, monitoring the absorption of a colored reactant at 520 nm . The reaction occurs in a 1.29-cm sample cell, and the only colored species in the reaction has an

You can view more similar questions or ask a new question.