Chem 313: Quantitative Analysis Student Competencies

Quantitative Chemical Analysis, 6th. Ed., Daniel C. Harris, 2002.

Chapter 1 Student competencies

Upon completion of this chapter, students should be able to:

• Know SI units, including prefixes ranging from 10¹² to 10^-12, and be able to inter-convert among units.
• Know the definitions of concentration units: molarity, molality, normality, formality, ppm, ppb, and % composition.  Be able to calculate and inter-convert among these.  Understand how these concentrations units are used for solutions and gases.
• Describe how to prepare solutions of given concentration.
• Understand and describe how to dilute a solution. 
• Carry out calculations for solution preparation.
• Know how to solve problems that require an understanding of solution stoichiometry.

Chapter 6 Student competencies

Upon completion of this chapter, students should be able to:

• Write and manipulate equilibrium constants from balanced chemical equations.
• Relate thermodynamic quantities, including enthalpy, entropy, and free energy, to equilibrium constants.
• Apply Le Châtelier’s Principle to systems disturbed from equilibrium, including temperature, pressure, and concentration changes.
• Define solubility and saturated solutions.
• Write reactions for solid salts dissolved in water, and the corresponding solubility product expression.
• Calculate the concentration of a dissolved species in a saturated solution.
• Calculate the concentration of a dissolved species in a saturated solution containing a common ion.

Chapter 7 Student competencies

Upon completion of this chapter, students should be able to:

· Explain the terms titrant, equivalence point, and end point, indicator, standardization, primary standard solution, blank titration, direct titration, and back titration.

· Perform rigorous stoichiometric calculations involved in volumetric analysis.

· Describe a Kjeldahl nitrogen analysis.

· Explain and give examples of spectrophotometric titrations.

· Explain p-functions.

· Perform rigorous stoichiometric calculations for a precipitation titration curve.

· Utilize a spreadsheet for calculation of a titration curve.

· Describe Volhard and Fajans endpoint detection for argentometric titrations.

Chapter 8 Student competencies

Upon completion of this chapter, students should be able to

· Explain how an inert salt can increase the solubility of an ionic compound.

· Calculate the ionic strength of a solution.

· Explain the terms activity and activity coefficient.

· Write equilibrium constant expressions in terms of activity.

· Utilize the extended Debye-Hückel equation for evaluating activity coefficients.

· Utilize interpolation and activity coefficient tables for evaluating activity coefficients.

· Utilize activity concepts for stoichiometric calculation of pH and solubility.

Chapter 9 Student competencies

Upon completion of this chapter, students should be able to

· Describe and write charge balance equations in solutions.

· Describe and write mass balance equations in solutions.

· Utilize systematic equilibrium procedures for stoichiometric calculation of pH and solubility.

· Utilize spreadsheets for the calculation of equilibrium concentrations for solutions.

Chapter 10 Student competencies

Upon completion of this chapter, students should be able to

· Calculate pH and pOH for strong acids and bases at moderate and low concentrations.

· Write equilibrium expressions for weak acids and bases, and calculate equilibrium concentrations and fractions of dissociation.

· Describe the properties of buffer solutions.

· Derive the Henderson-Hasselbalch equation from weak acid and weak base equilibrium expressions.

· Calculate the pH of buffer solution.

· Calculate the pH of a buffer solution with added strong acid or base.

· Explain what is meant by buffer capacity.

Chapter 11 Student competencies

Upon completion of this chapter, students should be able to

· Calculate pH, protonated, intermediate, and deprotonated concentrations for diprotic acid systems.

· Utilize spreadsheets and successive approximations for calculating the pH, protonated, intermediate, and deprotonated concentrations for diprotic acid systems.

· Calculate pH for diprotic acid buffer systems.

· Explain the term isoelectric pH and isoionic pH for diprotic amino acids

Chapter 12 Student competencies

Upon completion of this chapter, students should be able to

· Utilize rigorous stoichiometric calculations to determine pH at various points in a strong acid/strong base titration.

· Utilize rigorous stoichiometric calculations to determine pH at various points in a weak acid/strong base titration.

· Utilize rigorous stoichiometric calculations to determine pH at various points in a strong acid/weak base titration.

· Determine and utilize spreadsheets for first and second derivative titrations curves in the detection of endpoint.

· Derive the Gran equation and construct Gran plots to determine acid ionization constants.

· Describe how to correctly choose an appropriate color indicator for titration experiments.

Chapter 14 Student competencies

Upon completion of this chapter, students should be able to

· Define oxidation and reduction, anode, and cathode.

· Balance oxidation-reduction reactions.

· Utilize concepts of charge, current, voltage, resistance, power, work, and free energy for problem-solving

· Describe the construction of a galvanic cell.

· Describe the function of a salt bridge.

· Describe the standard hydrogen electrode.

· Utilize standard reduction potentials to determine standard cell potentials.

· Utilize the Nernst equation to determine non-standard cell potentials.

· Utilize standard cell potentials to determine equilibrium constants.

Chapter 15 Student competencies

Upon completion of this chapter, students should be able to

· Describe silver-silver and calomel reference electrodes.

· Explain junction potential.

· Describe a glass electrode for pH measurement.

· Explain the calibration of a pH electrode and sources of error in pH measurements.

· Discuss the construction of several ion selective electrodes and utilize problem solving for quantitative measurements.

· Describe p and n-type semiconductors, and how FETs can be used as pH sensors.

Chapter 19 Student competencies

Upon completion of this chapter, students should be able to:

• Know how to calculate wavenumber, wavelength, frequency, and energy of a given photon.
• Understand the spectral regions associated with changes in electronic, vibrational, rotational, and magnetic energy levels.
• Explain on the atomic/molecular level, why atomic and molecular spectra are so different. Relate this to the methods necessary to measure atomic spectra.
• Understand absorption, spontaneous emission, and stimulated emission processes.
• Understand Beer's law and how to use it to determine an unknown concentration.
• Diagram single beam and double beam spectrometers and discuss how they are used to measure the absorbance of a sample.
• Explain why most organic liquids are clear and most organic solids appear to be white.
• Understand the relative energies of singlet and triplet states; discuss the relative probabilities of singlet-to-singlet and singlet-to-triplet transitions.
• Diagram the physical processes that can occur after a molecule has absorbed an ultraviolet or visible photon.  Use it to explain the basis for fluorescence and phosphorescence.
• For luminescent signals, relate the intensity of the emission source to signal strength.

Chapter 20 Student competencies

Upon completion of this chapter, students should be able to:

• Outline the steps taken to use Beer's law to determine the concentration of mixture components when the spectra are well resolved.
• Explain what isosbectic points are and how to identify them.
• Outline the steps for Job's method and what it is used for.
• Discuss flow injection analysis and the advantages / disadvantages of it.
• Discuss ELISA and the major advantages / disadvantages of it.  Understand how time-resolved fluorescence immunoassays are carried out and the basis for their use.
• Understand what is meant by quantum yield.  Discuss how luminescent quenching can be used to detect oxygen.  Diagram the layout and function of a portable instrument to do this.

Chapter 21 Student competencies

Upon completion of this chapter, students should be able to:

• Know how to use refractive indices to calculate the amount of light reflected at each interface.
• Use Snell's law to calculate changes in direction for refracted rays.  Use Snell's Law to determine the minimum critical angle for internal reflections to occur.
• Explain how internal reflection techniques work.
• Understand thermal radiation (black-body radiation).  Explain how the energy and wavelength of maximum intensity changes with temperature.
• Explain how a four-level laser works.
• Explain how grating monochromators and prisms work.  Explain how filters are used.
• Understand how photomultiplier tubes and silicon diodes are used to detect electromagnetic radiation.  Know the wavelengths that can be detected with silicon diodes.
• Explain how an FT-IR instrument works and the mathematical operations necessary to obtain an absorbance spectrum.
• Understand the relationship between sampling time and signal to noise ratio.

Chapter 22 Student competencies

Upon completion of this chapter, students should be able to:

• Explain the basis for atomic absorption and emission instruments.
• Describe the three methods to atomize samples in atomic spectroscopic instruments.
• Know the Boltzman distribution and use it to calculate relative populations of energy levels.  Understand how this relative population changes with temperature and with energy gaps.
• Explain how nebulizers and hollow cathode lamps work.
• Outline the potential interferences in atomic spectroscopy.  Discuss how background corrections are carried out.
• Understand the basis for line widths in atomic spectroscopy.
• Understand what matrix modifiers are used for.

Chapter 23 Student competencies

Upon completion of this chapter, students should be able to:

• Know the partition relation for solvent extraction procedures and be able to solve problems using it.
• Understand the use of pH adjustment for extraction procedures
• Understand what a distribution coefficient is, what systems it applies to, and how to use it.
• Understand and explain the basis for chromatography; define mobile and stationary phases, eluent, eluate, packed and open tubular columns.
• Understand and explain the basis for these types of chromatography:
• Adsorption chromatography
• Partition chromatography
• Ion-Exchange chromatography
• Molecular Exclusion chromatography
• Affinity chromatography
• From a given chromatogram, know how to calculate each of the following:
• Adjusted retention times
• Relative retention
• Capacity factor
• Partition coefficient
• Resolution
• Number of theoretical plates
• Plate Height
• Understand the van Deemter equation and apply it to various forms of chromatography.
• Understand the two major asymmetries associated with chromatographic band shapes and explain the underlying cause for each.
• Understand and explain the silanization process.

Chapter 24 Student competencies

Upon completion of this chapter, students should be able to:

• Diagram a gas chromatograph and be able to explain the features and functions of each component.
• Describe open tubular (WCOT and PLOT) and packed columns; be able to discuss the stationary phases most often used; Describe the most common applications for the various column types.
• Determine the retention index for a given compound.
• Discuss isothermal and temperature-programmed GC and the advantages of each.
• Understand the basis and applicability of split, split less, and on-column GC injection techniques.
• Understand, diagram, and describe the most important GC detectors to include TCD, FID, ECD and MS.
• Understand and describe solid-phase micro extraction (SPME) techniques; outline the advantages and disadvantages of SPME.
• Describe purge and trap GC.
• Understand the basis for GC method development.
• Understand and diagram the four major types of mass selectors and two ionization methods used in mass spectrometry.

Chapter 25 Student competencies

Upon completion of this chapter, students should be able to:

• Diagram the layout of an HPLC instrument and explain the design and function of each component.
• Explain why packed columns are used in lieu of open tubular ones for HPLC; identify and explain the effect of particle size on resolution and pressure.
• Discuss the effect of temperature on HPLC retention times and explain why a column heater is sometimes used.
• Describe the geometry of HPLC columns and the use of guard columns.
• Describe in detail the structure of silica particles.  Outline the pH limitations for the use of silica; identify the support particles used outside of silica's pH range.  Explain how bonded stationary phases can be attached to silica.  Identify the chromatographic technique that relies on bare silica.
• Explain what is meant by an eluotropic series and by eluent strength.
• Discuss normal-phase and reverse-phase HPLC. Understand the relation between eluent strength and polarity for both normal and reverse phase separations.
• Understand isocratic and gradient elution and the utility of each.
• Understand the steps taken to treat solvents in HPLC.
• Know what is meant by dead volume; what effect dead volume has on peaks, and what steps to take to minimize its effects.
• Explain how injection is accomplished in HPLC.
• Understand and describe the major detection schemes for HPLC to include refractive index, fluorescence, absorbance, and electrochemical.
• Describe and explain atmospheric pressure chemical ionization and pneumatically assisted electrospray techniques for introducing the liquid eluate from an LC column into a mass spectrometer.
• Compare the advantages and disadvantages of selective ion monitoring and full scan monitoring using MS detectors.
• Explain why 30 mM of triethylamine, ammonium acetate or triethyl ammonium acetate are sometimes added to an HPLC mobile phase.

Chapter 26 Student competencies

Upon completion of this chapter, students should be able to:

• Discuss the structure of ion exchange resins, the structure of strongly and weakly acidic cation exchangers, the structure of strongly and weakly basic anion exchangers, and the effect of increasing cross-linking on ion selectivity.
• Discuss cellulose and dextran ion exchangers; identify their features and the types of applications they are used for.
• Understand and explain the effects of charge, hydrated radius, and polarizability on ion-exchange selectivity.  Predict the relative values of selectivity coefficients for various ions and amounts of cross-linking.
• Explain what Donnan equilibrium is and the basis for ion exclusion chromatography.
• Outline the major applications of ion exchange.
• Discuss ion chromatography and the basis for suppressed anion and suppressed cation chromatography.
• Discuss the basis for separation in molecular exclusion (gel permeation) chromatography and the applications to which it is applied.
• Outline the basic principles and uses of affinity chromatography.