Packard AP Chemistry Final Exam Semester 2

the first ionization energy of an element is the energy required to remove an electron form a gasous atom of an element

Al + Mg --> Al + Mg

which of the following has the bonds arranged in order of decreasing polarity

H-F>N-F>F-F

Which of the substances listed above has the highest boiling point, and why?

HF, because its molecule form hydrogen bonds

The ideal gas law best describes the properties of which of the following gases

N2

In the reaction represented above, what is the hybridization of the C atoms beofre and after the reaction occurs

before sp^2 after sp^3

A sample of a solid labeled as NaCl may be impure. a student analyzes the sample and determines that it contains 75 percent chlorine by mass. Pure NaCl contains 61 percent chlorine by mass

the sample contains NaCl and LiCl

To determine the number of moles of Cu in the sample of the mixture, the students measured the absorbance of known concentrations of CuNO3 using a spectrophotometer

the student labelled the cuvettes incorrectly, reversing the labels of the solutions of known concentrations

IN one student's experiment the reaction proceeded at a much slower rate than it did in the other student's experiments

the student used a 1.5M solution of HNO3 instead of 15.8 solution of HNO3

Which of the following statements about (Delta)H for the reaction is correct?

(delta)H > 0 because energy is required to break the N-N bond

based on the formation in the table above, which of the folllowing shows the cell potential and Gibbs free energy change for the overall reaction that occurs in a standard galvanic cell?

+1.63 -944

If P(N2O4) is 1.33 atm when the system is at equilibrium at 70 degrees, which is P(NO2)

2.0 atm

When 4 L of He, 6 L of N2 and 10 L of Ar, all at 0 C and 1 atm, are pumped into an evacuated 8 L rigid container, the final pressure in the container at 0 is

2.5 atm

The students determined that the reaction produced .01 mol of CuNO3.

32%

If the absorbance of the mixture is .2 at 453 nm how many moles of fe were present in the 100 ml sample

4x10^_6

the complete photo electron spectra of neutral atoms of two unknown elements, X and Y are shown above. Which of the following can be inferred from the data

Element Y has a greater nuclear charge when element X does

Each student in a class is placed a 2 g sample of a mixture of CU and AL in fume hood. The students slowly poured15 ml of 15.8M HNO3 into their beakers

It is a redox reaction, because CU is oxidized and the nitrogen atom in NO3 is reduced

based on the diagram above, which of the following best helps to explain why MgO is not able to conduct electricity, but MgO is a good conductor of electricity

MgO consists of separate Mg ions and O ions held in a fixed lattice, but in MgO the ions are free to move and conduct electricity

On the basis of molecular structure and bond polarity, which of the following compounds is most likely to have the greatest solubility in water

NH3

Which of the following best predicts how the partial pressures of the reacting species will be affected if a small amount of Ar(g) is added to the equilibrium mixture at constant volume

No change will take place

O3(g) + O --> 2O2 (g) The decomposition of O3(g) in the upper atmosphere is represented by the equation above. The potential energy diagram for the decomposition of O3(g) in the presence and absence of NO(g) is given below. Which of the following mechanism for the catalyzed reaction is consistent with the equation and diagram above?

O3(g) + NO(g) ---> NO2(g) O2(g) slow NO2(g) + O(g) ---> NO(g) + O2(g)

The reaction between NO2(g) and CO(g) is represented above. The elementery steps of a proposed mechanism are represented below. Step 1: 2 NO2->NO+NO3 Step 3: NO3+CO->NO2+CO2 Which of the following is the rate law for the overall reaction that is consistent with the proposed mechanism?

Rate=k[NO2]2

The reactions represented above are carried out in sealed, rigid containers and allowed to reach equilibrium. If the volume of each container is reduced from 1.0L to .5L at constant temperature, for which of the reactions will the amount of products be increased?

Reaction A

If a pure sample of an oxide of sulfur contains 40 percent sulfur and 60 percent oxygen by mass, then the empirical formula of the oxide is

SO3

The table above provides some information about two types of steel, both of which are alloys of iron and carbon which of the following best helps to explain why high-carbon steel is more rigid than low carbon steel?

The additional carbon atoms, within the alloy make it more difficult for the iron atoms to slide past one another.

Which of the following statements best helps to explain why the contents of the tube containing the equilibrium mixture turned a lighter color when the tube was placed into an ice bath

The forward reaction is endothermic

CL+CLO+2H-->Cl2+H2O What effect will increasing H at constant temperature have on the reaction represented above?

The frequency of collisions of between H ions and CLO ions will increase

NO3+O3-->NO2+2O2 fast Cr2O7+3H2O<-->2CrO4+2 H3O orange....................yellow the equilibrium system represented by the equation above initially contains equal concentrations of CR2O7 and CrO4. Which of the following statements correctly predicts the result of adding a sample of 6.0M NaOH to the system and provides and explanation

The mixture will become more yellow because OH- will shift the equilibrium towards the products

The mass spectrum of an average sample of a pure element is shown in the figure above

Zr

A mixture of CO and O is placed in a container, as shown above. A reaction occurs, forming CO2. Which of the following best represents the contents of the box after the reaction has proceeded as completely as possible

[4-3 molecule, 1-2 molecule]

Based on structures shown above, which of the following statements identifies the compound with the higher boiling point and provides the best explanation for the higher boiling point

compound 2, because it forms hydrogen bonds, whereas compound 1 does not

at 298k and 1 atm, Br2 is a liquid with a high vapor pressure, and Cl2 is a gas

forces among Br2 molecules

A student is given a sample of a pure, white crystalline substance. Which f the following would be most useful in providing data at determine if the substance is an ionic compound

testing the electrical conductivity of an aqueous solution of the substance