1) During the adiabatic expansion of an ideal gas against atmospheric pressure, the internal energy will:
2) During the isothermal expansion of an ideal gas, the internal energy will:
3) During an exothermic chemical reaction inside a closed system the internal energy will:
4) The heat capacity at constant volume is ________ the heat capacity at constant pressure for an ideal gas:
5) The value of q for an isothermal ideal gas system when work is being done on that system is:
6) The enthalpy change of a system at constant pressure when 1.00 J of heat is transferred into it is:
7) When molecules which are used as the refrigerant in your refrigerator condense or associate with each other, they will:
8) The total entropy change for the spontaneous crystallization of sodium chloride from a water/ethanol solution is:
9) For a constant pressure system, if the entropy change for the surroundings is negative, then the process going on inside the system is:
10) When an open glass of water is cooled from 50 C to 20 C by putting the 50 C glass of water in a bath that is at 20 C, the entropy change of the glass of water is:
11) For the last problem (10) the absolute value of the entropy change in the bath is ___________ the absolute value of the entropy change in the glass of water:
12) At constant pressure and temperature, if the total entropy change for the system and surroundings during some process is positive then the free energy change for the process is:
13) The total entropy change for the reversible expansion of an ideal gas is:
14) When I dissolve salt in liquid water, the chemical potential of the water will:
15) At 0 C and 1 atm, the chemical potential of liquid water is ____________ the chemical potential of ice:
16) Exerting pressure on ice causes it to melt because the molar volume of ice is ____________ the molar volume of liquid water.
17) Adding salt to a mixture of ice and liquid water causes the temperature of the mixture to drop because:
18) A glass contains 1 mole of ice and 1 mole of liquid water at thermoequilibrium. After adding 1 Joule of heat to the system the temperature will:
19) The enthalpy change associated with mixing two different ideal gasses that start at the same temperature and pressure is:
20) If I add salt to water, the vapor pressure of the water will:
21) In a system with 5 phases that coexist at equilibrium, what is the minimum number of components that must be present?
22) The reason why reactions come to an equilibrium point instead of going entirely to products is:
23) When a system is at equilibrium, the reaction free energy is:
24) For a reaction Aß à B with a standard reaction free energy of 1kJ/mole, the equilibrium constant is.
25) For the same reaction as in problem 24, the standard reaction enthalpy is:
26) One finds that the equilibrium constant for a particular reaction increases with increasing temperature. Assuming that the standard reaction enthalpy and entropy are temperature independent, this means that:
27) At 20 C, the concentration of OH- is 10-4 M. What is the pH?
28) In a 0.1 M solution of NaCl in water, you expect the activity of Na+ to
be _________ 0.1
29) For the elementary reaction, A+Bà C, the units of the forward rate constant are:
30) The energy per photon of red light is __________ that of blue light.
31) The most common reason why an absorbance spectrum of a molecule at room temperature in solution has a width to it is:
32) The reason why metals are so shiny is:
33) Molecules generally fluoresce at wavelengths longer than they absorb because:
Each of the following numerical problems are worth 25 points. You must show your reasoning for credit.
34) For a reversible, isothermal expansion of 1 mole of an ideal gas from 5 liters to 10 liters at a temperature of 25 C, what is
a) the internal energy change?
b) enthalpy change for the system
c) work
d) heat
e) entropy change for the system
35) A container with 10 moles of liquid water initially at 25 C is cooled to -25 C ice at constant pressure. Calculate the
a) entropy change of the system
b) enthalpy change of the system
c) q for the process
36) The initial rate of B formation in the elementary reaction Aß à B is 0.10 M/s. The initial concentrations of A and B were [A0] = 1.00 M and [B0] = 0.00 M . The final concentration of A (after equilibration) is 0.20 M.
a) What is the equilibrium constant for this reaction?
b) What is the forward rate constant for this reaction?
c) What is the backward rate constant for this reaction?
37) There are a number of dye molecules whose absorbance changes radically with pH. Let's consider a dye that is a weak acid and only absorbs at 500 nm in the protonated form (AH + H2O ß à A- + H3O+, only AH absorbs light) . The dye has a pKA of 6.00 and the extinction coefficient of the dye at 500 nm is 5.00 x 103 M-1cm-1.
a) If the total concentration of the dye is 1.00 mM (i.e., [A-] + [AH] = 0.00100 M), what is the absorbance of the dye solution at pH 5.5 in a 1 cm cuvette at 500 nm?
b) If 1 microwatt (10-6 Joules/second) of 500 nm light entered the cuvette described above, how many photons per second would be transmitted through the cuvette?