ASU CHM 343 – Outline of Quiz Questions

Spring 2026

Quiz 1

estimated error (uncertainty) in graduated cylinder measurement (reference Error Analysis Review)
1.0 ml of distilled water (density = 0.997) was pipetted 10 times and weighted on a calibrated Mettler-Toledo XSR105 balance (+/- 0.01 mg). This data was recorded and saved as an ascii (csv) file on the CHM343 GitHub Data repository: 2024_08_24_Weight_1ml_Water_Pipette_Data.txt. What is the uncertainty (one standard deviation) of this pipette in delivering 1 ml of water?
Propagation of error in density from measured mass and volume (reference Error Analysis Review)
An experimental measurement of the rate constant from temperatures between 300-350 K have been recorded and saved as an ascii (csv) file on the CHM343 GitHub Data repository: Temp_Rate_Constant_kerr_Example_Data_CHM343.txt. Use nonlinear least-squared curve fitting of the data to determine the activation energy.
A recent paper in the Journal of Chemical Education (2026) was published entitled: “Spectrometer Assembly and Python-Based Data Science Lab on the Reduction Kinetics of Methylene Blue”. Do a literature search and obtain this paper and all the associated supporting information. Reproduced figure 6c and determine the associated pseudo-first-order rate constant (k_exp) and report the value below in units of min^-1.

Quiz 2

Which is the appropriate thermodynamic condition for the propagation of sound in a gas? isothermal, isobaric, isenthalpic, or adiabatic (students should be able to justify/explain their answer)
If the length of a closed acoustic interferometer tube (Kundt tube) is L, what is the wavelength of the lowest frequency resonance mode?
The 4 most commonly used modern refrigerant gases are difluromethane (R32), 1,1-difluoroethane (R152a), 1,1,1,2-tetrafluoroethane (R134a), and 2,3,3,3-tetrafluoropropene (R1234yf). Which of these molecular gases has the greatest vibrational contribution to its heat capacity at standard temperature and pressure (STP)? Note: Students should do standard optimization and vibrational computational chemistry on each of these molecular gases using an electronic structure computational package (i.e., molcalc.org, RowanSci.com, chemcompute.org, ORCA, Psi4, or Gaussian)
In the case of oxygen and ethane gas, they have very similar mass and sound velocities, so the effect of heat capacity is the dominant distinguishing factor. What molecular degree of freedom most contributes to the decrease in the speed of sound of ethane gas compared to oxygen gas? (and hence the increase in the heat capacity of ethane gas compared to oxygen gas at standard temperature and pressure, STP). Students should do standard optimization and thermodynamic computational chemistry on each of these molecular gases using an electronic structure computational package (i.e., molcalc.org, RowanSci.com, chemcompute.org, ORCA, Psi4, or Gaussian)
The speed of sound of various gases is experimentally measured using an acoustic interferometer. In order to use an acoustic interferometer to obtain accurate experimental measurements of a gases sound velocity, it is critical to have an accurate and precise determination of the length (L) of the acoustic interferometer tube. Measuring the length with a ruler, for example, does not provide an accurate enough determination of the tube length. What is commonly done is to start with a gas that has a known sound velocity and use it to calibrate and/or measure the length of the acoustic interferometer tube to a high accuracy. Argon gas is most commonly used, and has a known sound velocity of 320.0 m/s at 23C. Use the following experimental data uploaded to GitHub (Argon_Gas_acoustic2_pchem_dev_WN_22kHz_100vol_SensorsData.csv) to determine an accurate acoustic interferometer tube length for the acoustic2.pchem.dev system.

The image of the components for a remote acoustic interferometer (acoustic2.pchem.dev) are shown along with a ruler next to the polycarbonate tube. This visually shows that the tube is roughly 1 foot. Above the polycarbonate tube with end caps is the gas valves and the microcontroller.

Quiz 3

Using molcalc.org (AM1 semi-empirical method), determine the standard enthalpy of formation ( $Δ H_{f}$ ) of Benzoic Acid. Report the computed value in kJ/mol. (This is a good chance to repeat this computation using ASU SOL (Gaussian 16), Rowan, ChemCompute at the HF and DFT level of theory to see the accuracy of computational thermochemistry).
The known enthalpy of formation of Benzoic Acid is -385 kJ/mol (reported by NIST). When you use quantum computational chemistry semi-empirical methods (i.e., AM1, PM6) to determine the enthalpy of formation of Benzoic Acid, you will typically end up getting a value that is significantly different (determined in one of the lab 2 quiz questions using molcalc.org). What is the primary reason for this large difference between the literature value and the value determined from quantum computational chemistry semi-empirical methods (i.e., AM1, PM6)?
The bomb calorimetry simulator. is designed to provide data that is indistinguishable from what would be measured experimentally with a standard Parr bomb calorimeter. A simulated data set for the combustion of Benzoic Acid with an initial sample weight of 2.0 g, initial water temperature of 24.0^oC, initial ignition wire weight of 0.028 g and final ignition wire weight of 0.023 g has been uploaded to the CHM 343 GitHub Data repository (Bomb_Cal_Data_Benzoic_Acid_cc0001.csv). Using this data, determine the temperature change ( $Δ T$ ) for this simulated experiment. Report the value of $Δ T$ in Kelvin (K).
The bomb calorimetry simulator. is designed to provide data that is indistinguishable from what would be measured experimentally with a standard Parr bomb calorimeter. A simulated data set for the combustion of Benzoic Acid with an initial sample weight of 2.0 g, initial water temperature of 24.0^oC, initial ignition wire weight of 0.028 g and final ignition wire weight of 0.023 g has been uploaded to the CHM 343 GitHub Data repository (Bomb_Cal_Data_Benzoic_Acid_cc0001.csv). Benzoic acid has a well known heat of combustion and is therefore typically used to determine the calorimeter constant. Using this simulated data, determine the simulated bomb calorimeter constant (for Calorimeter Code 0001) in kJ/K and report the value below.
Using the bomb calorimetry simulator. (with Calorimeter Code 0001), simulate data sets for the combustion of Naphthalene and Azulene. Students should used calorimeter code 0001 because the bomb calorimeter constant has already been determined in a previous quiz question. From this simulated data, determine the molar heats of combustion for both naphthalene (naph) and azulene (azul). Using the the molar heats of combustion for both naphthalene and azulene determined from the simulated data, compute the enthalpy change for the isomerization reaction:
- $C_{10} H_{8} (s, n a p h) ⟶ C_{10} H_{8} (s, a z u l)$
- Report numerical answer in units of kJ/mol below.
- In the supplemental information section of your lab 2 notebook/report, include all the simulated data, data analysis and calculations associated with determining an answer to this quiz question (10 pts extra credit).

Quiz 4

Information updated the week of April 20, 2026.