1. Compute the change in Gibbs free energy for reaction of 2.6 kg of ocean (liquid water) with the atmosphere (nitrogen and oxygen) to form aqueous nitric acid (H+ and NO3-) under standard thermodynamic conditions at 298.15 K. The standard Gibbs Free Energy of formation for nitrate ion in aqueous solution is -111.3 kJ/mol.
( answer must be in KJ )
2. A Carnot engine heat engine absorbs 1500.0 J from the high temperature reservoir at 580.0 K and discharges waste heat to a low temperature reservoir at 350.0 K. How much waste heat is discharged? (Express your value as a positive number.)
( answer must be in J )
3. A Carnot heat engine extracts 12.3 J from a 540.0 K heat reservoir and converts it to 3.8 J of work. Compute the temperature of the low-temperature heat reservoir of the engine.
( answer must be in K )
4. An unknown substance has a measured specific heat that varies as a function of temperature and is equal to 0.85*T(J/kg/K). What is the entropy change of this substance when the temperature of 0.94 kg of the substance is raised from 27 K to 50 K?
( answer must be in J/K )
5. Compute the standard change in Gibbs free energy for the reaction 2 NO2(g) → N2O4(g) at 40 C.
|
Molecule
|
ΔfH0
kJ/mol
|
S0
J/mol K
|
|
NO2
|
33.2
|
240.1
|
|
N2O4
|
11.1
|
304.4
|
(answer must be in kj/mol)
6.What is the total change in entropy of the universe (system + surroundings) if 4.3 g of CO(g) reacts completely with O2(g) to form CO2(g) under standard conditions (25 C, 1.0 bar, ideal gases)?
(answer must be J/K )
7. On average, what percentage of random rolls of three (3) regular playing dice should result in a combined value of 10?
( answer must be in percent )
8. Suppose that you wish to cool 0.31 mol of ideal monatomic gas, initially at 69 C and 1 bar, by reversible isothermal compression to some volume V followed by reversible adiabatic expansion back to its original volume. What compressed volume V is required to achieve a final temperature of 10 C?
( answer must be in L )
9. Using the statistical definition of entropy, compute the change in entropy of helium gas (initially at 33 C and 0.93 bar) when it undergoes free expansion from 1.7 L to 3.6 L. Assume that under these conditions, helium behaves as an ideal gas and that the total number of microstates is proportional to the volume of the container.
( answer must be in J/K )
10. On average, what percentage of random rolls of two (2) regular playing dice should give a combined total of 5?
(answer must be in percent )