F
An isolated system allows for the flow of …?
a) heat b) kinetic energy c) none of these d) matter
c) none of these
Consider the processes
I) NaCl(s) → Na+ (aq) + Cl─(aq)
II) CaCO3(s) → CaO(s) + CO2(g)
III)H2O(l) → H2O(s)
Which entropy will increase as the process proceeds from left to right?
a) I only b) I, II c) III only d) I, II, III
b) I, II
Which of the following statements about bond energy calculations is NOT true?
a) They are a way to calculate heats of reaction
b) They do not consider intermolecular force interactions
c) The calculation involves summing the reactant bond energies and subtracting the product bond energies
d) The table of bond energies includes multiple values for the same bond energy
d) The table of bond energies includes multiple values for the same bond energy
Calculate the ΔHrxn for the theoretical reaction of
C --- > 2A + B
Given
C --- > B + D ΔHrxn = 200 kJ
2A --- > D ΔHrxn = -200 kJ
a) 0 kJ b) 400 kJ c) -400 kJ d) 200 kJ
b) 400 kJ
An isolated system allows for the flow of …?
a) heat b) kinetic energy c) none of these d) matter
c) none of these
The volume of a piston in an internal combustion engine increases in volume by 100 ml against a pressure of 20 atm. What is the work done? (Conversion factor: 1 liter-atm = 100J)
a) 200 J of work done on the system
b) 200 J of work done by the system
c) 2 J of work done on the system
d) 2 J of work done by the system
b) 200 J of work done by the system
Which of the following statements is not true concerning the second law of thermodynamics?
a) The entropy of the surroundings is determined by the entropy of the system
b) A perfect crystal at 0 K has an absolute entropy of 0
c) The number of microstates in the universe is always increasing
d) The entropy of the universe is always increasing.
a) The entropy of the surroundings is determined by the entropy of the system
Which one shows the substances in the decreasing order of their molar entropy?
a) H2O(l) >CO2(g) > Ne(g) > Ar(g)
b) CO2(g) > Ar(g) > Ne(g) > H2O(l)
c) CO2(g) > H2O(l) > Ne(g) > Ar(g)
d) H2O(l) > Ne(g) > Ar(g) > CO2(g)
b) CO2(g) > Ar(g) > Ne(g) > H2O(l)
Which of the following statements is/are true concerning the first law of thermodynamics?
I) The internal energy (E) of the universe is conserved.
II) The internal energy of a system plus that of its surroundings is conserved.
III)The change in internal energy (∆E) of a system and its surroundings can have the same sign.
a) I, III b) I only c) I, II, III d) I, II
d) I, II
Which of the following lists contains ONLY path functions?
a) heat, work, temperature
b) work, pressure
c) heat, work
d) pressure, temperature
c) heat, work
Dr. Laude explodes a gummy bear in a bomb calorimeter. The temperature increase for the 250 grams of water surrounding the calorimeter is 20 degrees. The bomb housing has a heat capacity of 250 J/℃. How much energy is in a gummy bear? (The heat capacity of water is 4 J/g℃)
a) 250 kJ b) 25 kJ c) 20 kJ d) 200 kJ
b) 25 kJ
A hydrogen balloon explodes at room temperature releasing 600 kJ of energy to the surroundings. What is the ΔSsurr?
a) -2 kJ/K b) 2 kJ/K c) 2 J/K d) -2 J/K
b) 2 kJ/K
Without performing any calculations, determine whether the entropy of the system increases or decreases in:
Cl2(g) + H2O(l) → HCl(aq) + HOCl(aq)
a) Decreases
b) Increases
c) Unable to determine
d) The entropy does not change
a) Decreases
Which of the following statements is NOT true about thermodynamic sign conventions?
a) ∆H and ∆S can be used to determine the spontaneity of a reaction
b) When a liquid becomes a gas, ∆S is positive and the system is becoming more disordered
c) An increase in system entropy and work being done on the surroundings have the same sign
d) A reaction that is exothermic has a negative sign for ∆H
c) An increase in system entropy and work being done on the surroundings have the same sign
Which of the following statements is/are true concerning the first law of thermodynamics?
I) The internal energy (E) of the universe is conserved.
II) The internal energy of a system plus that of its surroundings is conserved.
III)The change in internal energy (∆E) of a system and its surroundings can have the same sign.
a) I, III b) I only c) I, II, III d) I, II
d) I, II
Which of the following is NOT TRUE about heats of formation for a compound?
a) All reactants and products must be one mole quantities.
b) The reactants in a formation reaction are elements in their standard states.
c) Standard conditions in a formation reaction are 1 atmosphere and 298K.
d) Formation reactions produce a mole of product that can be in any state.
a) All reactants and products must be one mole quantities.
What are the signs of ΔG, ΔH, and ΔS for water condensing at 105℃?
H2O(g) → H2O(l)
a) +, ─, ─ b) ─, ─, ─ c) +, +, + d) ─, +, ─
a) +, ─, ─
What are the ΔSuniv, ΔSsys, ΔSsurr for
H2O(s) → H2O(l) at -10℃?
Hint: the first step is to ask whether the reaction is spontaneous.
a) +, ─, ─ b) ─, ─, ─ c) ─, +, ─ d) The universe is too large to make this determination
c) ─, +, ─
Which of the following statements about internal energy and enthalpy is NOT true?
a) DE and DH have similar values when there is no change in the moles of gas for the chemical or physical process.
b) DH = qp and DE = qv in calorimetry measurements.
c) DH is appropriate for measuring changes in energy in closed systems.
d) DE and DH both account for system changes in potential energy and kinetic energy
c) DH is appropriate for measuring changes in energy in closed systems.
A syringe increases in volume by 3 liters at a constant pressure of 10 atm. Calculate the work in J. (1 liter-atm = 100 J).
a) 3000 J of work on the system.
b) 3000 J of work on the surroundings.
c) 300 J of work on the system.
d) 300 J of work on the surroundings.
b) 3000 J of work on the surroundings.
Which of the following compounds has the greatest absolute molar entropy?
a) A mole of hexane (C6H14) in the gas phase
b) A mole of hexane (C6H14) in the liquid phase
c) A mole of cyclohexane (C6H12) in the gas phase
d) A mole of cyclohexane (C6H12) in the liquid phase
a) A mole of hexane (C6H14) in the gas phase
You are making a plaster of Paris cast of a footprint at a crime scene and notice that the plaster of Paris has become quite warm when water is added. What would you predict as the temperature dependence for the chemical reaction? The balanced equation is shown below.
CaO(s) + H2O(g) --> Ca(OH)2(s)
a) This reaction occurs at any temperature.
b) This reaction does not occur at any temperature.
c) This reaction is more likely to occur at higher temperature.
d) This reaction is more likely to occur at lower temperature.
d) This reaction is more likely to occur at lower temperature.
Use the reaction below to assist with your reasoning. 2H2(g) + O2 (g) → 2H2O(g)
a) That makes no sense. Hydrogen balloons should explode even more at higher temperatures.
b) Combustion of H2 gas has a negative entropy and therefore an upper limit for the temperature at which the reaction can occur.
c) Combustion of H2 has a negative enthalpy and therefore an upper limit for the temperature at which the reaction can occur.
d) Combustion of H2 does work on the system and therefore an upper limit for the temperature at which the reaction can occur.
b) Combustion of H2 gas has a negative entropy and therefore an upper limit for the temperature at which the reaction can occur.
What is the work done when a volume decreases from 100 liters to 90 liters at 4 atm of pressure? (Conversion factor: 1 liter-atm = 100 J)
a) 4000 J of work done on the system
b) 4000 J of work done by the system
c) 400 J of work done on the system
d) 400 J of work done by the system
a) 4000 J of work done on the system
When the internal energy of a system decreases by 300 J while 100 J of work is done on the system, what is the change in heat for the system?
a) -200 J b) +400 J c) -400 J d) +200 J
c) -400 J