Problem 1: Heat capacity of a sample at constant volume ( C_v ) relates the following quantities:
Answers:

• Work performed by the sample to the change in its temperature
• The total internal energy of the sample to its absolute temperature
• A change in internal energy of the sample to the change in its temperature

Problem 2: Find which statement is correct:
Answers:

• C_V is the slope of the enthalpy-vs-temperature curve
• C_P is the slope of internal energy-vs-temperature curve
• the slope of enthalpy or internal energy-vs-temperature curve depends on whether the temperature is measured in K or Celsius units.
• C_P is the slope of the enthalpy-vs-temperature curve

Problem 3: What is the molar heat capacity of water at 291 K in J/(K mol)?
Answers:

• 41.5 kJ/(K mol)
• 75 J/(K mol)
• 0.24 J/(K mol)
• 44 J/(K mol)
• 4.184 J/(K mol)

Problem 4: When a chemical bond is formed, the enthalpy of the system changes in the following way:
Answers:

• it becomes lower
• it goes up or down depending on the type of chemical bond
• it becomes higher

Problem 5: Heat transferred to a system at constant pressure results in the following:
Answers:

• Internal energy increase and work of expansion
• All listed outcomes are possible
• All heat is converted to work
• Enthalpy decrease
• Entropy reduction

Problem 6: The standard enthalpy of crystallization of a drug from its aqueous solution is -50 kJ/mol. Is the process of dissolution of the drug crystals in water exothermic or endothermic?
Answers:

• no heat will be produced or absorbed
• endothermic
• cannot be established from crystallization enthalpy
• exothermic

Problem 7: The molar enthalpy of drug dissolution in water is 0.6 kcal/mol, and the molecular weight of the drug is 400 g/mol. How much heat will be absorbed when 1g of this drug is dissolved in 1L of water?
Answers:

• 0.25 kcal
• 0.6 kcal
• 0.6 cal
• 1.5 cal
• 1.5 kcal

Problem 8: Calorimetric data on binding of several anti-HIV drugs to their common target, HIV protease, is given in the table below (all values in kcal/mol measured at room temperature). Upon addition of 2 mmol of Saquinavir to the solution of its target protein, HIV-1 protease, at room temperature, 0.6 cal of heat was absorbed. Assuming the binding reaction has 1:1 stoichiometry, how much protein-drug complex was formed?

Answers:

• 0.6 mol
• impossible to tell
• 0.5 mmol
• 2 mmol
• 1.2 mmol

Problem 9: The standard heat of formation, a.k.a. the enthalpy of formation, of a drug at 25 deg. C is known. What else is needed to estimate its heat of formation at a higher temperature of 40 deg. C?
Answers:

• its heat capacity at constant volume C_V
• the temperature difference
• its heat capacity and the standard pressure
• its heat capacity at constant pressure C_P

Problem 10: Molar enthalpies of formation of liquid formic acid at 293K and 323K are -425 kJ/mol and -422.03 kJ/mol, respectively. Estimate the molar heat capacity at constant pressure (C_p,m ) of liquid formic acid in the 293-323 K temperature range.
Answers:

• -100 kJ/(mol K)
• 100 kJ/(mol K)
• 0.99 J/(mol K)
• impossible to determine
• 99 J/(mol K)

Problem 11: Compare the enthalpy of ammonium nitrate salt (nitrate salt of the ammonium cation) before and after dissolution in water and choose the right answer. How one can characterize the dissolution process?
Answers:

• H goes up and the process is exothermic
• H does not change and the solution gets colder
• H goes down and the process is endothermic
• H goes up and the process is endothermic