Final Exam Practice Questions

Technetium-99m, Tc-99m, is a radioactive isotope that is widely used in radiology. It has a half-life of 6 hours, and decays via a first order process. If a patient is injected with a 100 mg of Tc-99m, what will the amount of Tc-99m be after 24 hours.

• 50.0 mg

• 12.5 mg

• 25.0 mg

• 6.25 mg

What effect does the addition of a non-volatile, non-electrolyte solute have on the boiling point of a solvent?

• Increases the boiling point

• Decreases the boiling point

• It does not effect the boiling point

• It will depend on the identity of the solvent

Select the answer that best describes following unit cells,

• Unit cell 1 is a face-centered cubic (fcc)

• Unit cell 1 only has 1 atom located with the lattice

• Unit cell 2 is a hexagonal cubic system

• Unit cell 3 has 5 atoms located within the lattice.

Select the best statement regarding a reaction of A --> B with the concentration vs time profile depicted to the right.

• rate = k[A]

• rate = k[A]^2

• rate = k[A][B]

• rate = k[A]^2[B]

If a reaction has a rate law of rate = [A][B]^2 what would happen to the rate if the concentration of A is halved and the concentration of B is doubled?

• The rate would remain the same.

• The rate would double the same

• The rate would triple the same

• The rate would decrease by 1/2 the same

A reaction with an equilibrium constant Kp = 2.8 x 10^3 would consist of which of the following at equilibrium.

• Essentially all reactants

• Approximately equal reactants and products

• Some reactants and products with reactants favored

• Some reactants and products with products favored

A solution of NaOh has a concentration of 0.0010 M. Calculate the pH of the solution.

• 3.00

• 11.00

• 14.00

• 7.00

For the heterogeneous equilibrium PbCL2(s) <---> Pb 2+(aq) + 2Cl-(aq), which statement is true?

• The equilibrium constant is not affected by changes in the amount of PbCl2, so long as some is present.

• The equilibrium constant expression will not include the concentration of PbCl2 as it will be defined as 1.

• Adding more Cl-(aq) will shift the equilibrium to produce more PbCl2(s)

• All the statements above are true.

Identify the acid/conjugate base pair in the reaction

CH3COOH (aq) + OH- (aq) <---> CH3COO- (aq) + H2O (aq)

• CH3COO- and H2O

• CH3COOH and CH3COO-

• OH- and H2O

• CH3COOH and OH-

The phase diagram for carbon dioxide is shown to the right. A sample of solid carbon dioxide at 1 atm and -300^o C is heated at constant pressure until the temperature reaches 0^o C. This phase changes that occur during this process is/are best described as,

• Solid ---> Liquid --> Gas

• Liquid ---> Supercritical Fluid

• Solid --> Gas

• Solid ---> Supercritical Fluid