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Contact Information

Eric C. Person
Dept of Chemistry
2555 E. San Ramon
MS SB70
Fresno, CA
93740-8034

eperson@csufresno.edu
Office Phone: 559.278.2170
Dept Phone: 559.278.2103
Fax: 559.278.4402

 

 

Analytical Chemistry Readiness

The purpose of this self-test is to help you assess and review some of the skills from Chem 1A/1B or 3A that will be the most important for your success in Chem 102 or 105.  This self-test is not comprehensive, but should challenge you on the most critical concepts. The super and subscripts do not appear correctly in HTML.  If you would prefer the test is also avaliable in PDF format.

Instructions: Answer each of the following questions showing your work.  Remember to report your answers with an appropriate number of significant figures and the correct units. Use IUPAC atomic weights from http://www.chem.qmul.ac.uk/iupac/AtWt/

  1. Calculate the molar mass of magnesium sulfate heptahydrate.
  2. Consider the precipitation equilibrium AgCl(s) = Ag+(aq) + Cl-(aq). Qualitatively describe the effect adding each of the following species to a saturated AgCl solution will have on the solution concentration of chloride (e.g. increase, decrease, no change).
    a. 0.050 gram of AgCl(s)
    b. 5.0 mL of 0.100 M AgNO3(aq)
  3. How much solid silver nitrate (AgNO3, FW=169.8731 g/mol) must be dissolved in 100.0 mL of water to yield a 0.100 M solution of silver ions?
  4. A calibration plot of absorbance (y-axis) as a function of concentration (x-axis), also known as a Beer’s Law plot, gives a good linear fit with a slope of 362 M-1 and an intercept of 0.003. Calculate the concentration of an unknown sample with an average absorbance reading of 0.672. Report your answer in units of mM.
  5. Fill in the missing values for the following table. Be sure to show the equations you are using for your calculations. Hints: (1) Remember that H3O+ is the solution form of H+. (2) Remember that the acid dissociation constant for water in water (KW) is 1.0·10-14.
    pH [H3O+] [OH-]
    8.00 1.0·10^-8 M 1.0·10^-6 M
    3.72    
      5.9·10^-5 M  
        2.4·10^-6 M
  6. A solution of hydrochloric acid is standardized by titration. The endpoint is reached after adding 32.65 mL of 0.1004 M NaOH to 25.00 mL of the unknown solution. Calculate the concentration of the hydrochloric acid solution.
  7. Solve the following equations for x, the concentration of an analyte in units of molarity.
    a. 1.8·10-10 = x2
    b. 1.8·10-10 = x * (x + 0.0050)
    c. 1.75·10-5 = x2 / (0.010 - x)
    d. 4.756 = -log x