WorksheetsChem Review
Total questions: 46
Worksheet time: 26mins
Refer to the following diatomic species
Li2, B2, N2, O2, F2
Which has the largest bond-dissociation energy?
Li2
B2
N2
O2
F2
Which of the following statements is a correct interpretation of the data regarding how the order of the reaction can be determined?
The reaction must be first order because there is only one reactant species.
The reaction is first order if the plot of ln [H2O2] versus time is a straight line.
The reaction is first order if the plot of [1/H2O2] versus time is a straight line
The reaction is second order because 2 is the coefficient of [H2O2] in the chemical equation.
Which of the following Lewis electron dot diagrams represents the molecule that contains the smallest bond angle?
CF4
NF3
SO3
So2
Solid Al(No3)3 is added to distilled water to produce a solution in which the concentration of nitrate, [NO3], is at .10 M. What is the concentration of alluminum in this solution?
0.010 M
0.033 M
0.066 M
0.10 M
0.30 M
Which of the following is least soluble in water?
CO(H3C)2
CCl4
OH(H3C)
O(H3C)(CH3)
Factors that affect the rate of a chemical reaction include which of the following?
I. Frequency of collisions of reactant particles
II. Kinetic energy of collisions of reactant particles
III. Orientation of reactant particles during collisions
II only
I and II only
I and III only
I, II, and III
X2 +Y2 -> X2Y2 rate = k[X2]
A reaction and its experimentally determined rate law are represented above. A chemist proposes two possible mechanisms for the equation.
Based on the information which of the following is true.
Only mechanism 1 is consistent with the rate law
Only mechanism 2 is consistent with the rate law
Both mechanism 1 and 2 are consistent with the rate law
Neither mechanism 1 nor 2 is consistent with the rate law.
Element - Electronegativity
H - 2,1
C - 2.5
S - 2.5
F - 4.0
Cl - 3.0
Si - 1.8
On the basis of the information above, which of the following arranges the binary compounds in order of increasing bond polarity?
CH4 < SiCl4 < SF4
Ch4 < SF4 < SiCl4
SF4 < CH4 < SiCl4
SiCl4 < SF4 < CH4
Based on the data in the tables above, which of the following statements provides the best prediction for the boiling point of NaCl?
NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF
NaCl will have a boiling point between that of NaF and MgO because the covalent character of the bonds in NaCl is intermediate between that of MgO and NaF
NaCl will have a higher boiling point than MgO because the ions are spread farther apart in NaCl
NaCl will have a higher boiling point that MgO because the energy required to transfer electrons from the anion to the cation is larger in NaCl than in MgO.
2 O3 -> 3 O2 overall reaction H = -283 kj/mol
Which of the following reaction energy profiles best corresponds to the proposed mechanism?
Graph A
Graph B
Graph C
Graph D
The distribution of speeds of H2(g) molecules at 273 K and 1 atm is shown in the diagram above. Which of the following best shows the speed distribution of He(g) atoms under the same conditions of temperature and pressure?
If the oxygen isotope has a half-life of 15 seconds what fraction of a sample of pure O remains after 1.0 Minutes
1/2
2;4
7;30
1/8
1/16
The table above shows the results from a rate study of the reaction X + Y -> Z Starting with known concentrations of X and Y in experiment 1, the rate of formation of Z was measured. If the reaction was first order with respect to X and second order with respect to Y, the initial rate of formation of Z in experiment 2 would be
R
2R
4R
The data in the table above were obtained for the reaction X + Y -> Z. Which of the following is the rate law for the reaction?
Rate = k[X]^2
Rate = k[Y]^2
Rate = [X][Y]
Rate = k[X]^2[Y]
Rate = k[X][Y]^2
Which of the following complete Lewis diagrams represents a molecule containing a bond
angle that is closest to 120o?
Pure substance X decomposes according to the equation above. Which of the following graphs indicates that the graph is second order in X?
[X] Is a straight line
[X] Is linear increasing
[X] Is linear decreasing
1/[X] is linear Increasing
1/[X] is linear decreasing
The rate law for the reaction of nitrogen dioxide and chlorine is found to be rate = k[NO2]^2[Cl2]. By what factor does the rate of the reaction change when the concentrations of both NO2 and Cl2 are doubled?
2
3
4
6
8
After all of the Li(s) has reacted with H2O(l), the solution in the flask is added to a clean dry buret and used to titrate an aqueous solution of a monoprotic acid. The pH curve for this titration is shown in the diagram below
Using 125 mL of water instead of 100 mL
Using a .25 g sample of Li(s) instead of a .35 g sample
Using a 0.35 g sample of Li(s) cut into small pieces.
Decreasing the water temperature before adding the Li(s)
According to the rate law for the reaction, an increase in the concentration of hybronium ion has what effect on this reaction?
The rate of reaction increases.
The rate of reaction decreases.
The value of the equilibrium constant increases.
The value of the equilibrium constant decreases.
When the concentration of substance B in the reaction above is doubled, all other factors being held constant, it is found that the rate of the reaction remains unchanged. The most probable explanation for this observation is that
The order of the reaction with respect to substance B is 1
substance B is not involved in any of the steps in the mechanism of the reaction
substance B is not involved in the rate-determined step of the mechanism, but is involved in subsequent steps
substance B is probably a catalyst, and as such, its effect on the rate of the reaction does not depend on its concentration
Lewis electron-dot diagrams for CO2 and SO2 are given above. The molecular geometry and polarity of the two substances are
the same because molecular formulas are similar
the same because S and C have similar electronegativiteies
Different because the lone pair of electrons on the S
different because S has a greater number if electrons than C has
A proposed mechanism for destruction of ozone gas in the stratosphere is represented above. Which of the following is evidence that the mechanism is occuring?
The presence of Cl increases the rate of the overall reaction.
The presence of Cl decreases the rate of the overall reaction.
The presence of Cl increases the equilibrium constant of the overall reaction.
The presence of Cl decreases the equilibrium constant of the overall reaction.
According to the information in the table above, a 1.00 g sample of which of the following contains the greatest mass of oxygen?
Na2O
MgO
K2O
CaO
Consider atoms of the following elements. Assume that the atoms are in the ground state.
The atom that contains only one electron in the highest occupied energy sublevel.
S
C
Ga
Sb
Br
The table above shows the first ionization energy and atomic radius of several elements. Which of the following best helps to explain the deviation of the first ionization energy of oxygen from the overall trend?
The atomic radius of oxygen is greater than the atomic radius of flourine.
The atomic radius of oxygen is less than the atomic radius of nitrogen.
There is repulsion between paired electrons in oxygen's 2p orbitals.
There is attraction between paired electrons in oxygen's 2p orbitals.
Which has two lone pairs of electrons?
H2O
NH3
BH3
CH4
Graph ln [Z] is linear decreasing.
Consider the reaction represented by the equation 2 X + 2 Z -> X2Z2. During a reaction in which a large excess of reactant X was present, the concentration of reactant Z was monitored over time. A plot of the natural logarithm of the concentration of Z versus time is shown in the figure above. The order of the reaction with respect to reactant Z is
zero order
first order
second order
third order
Which of the following compounds contains both ionic and covalent bonds>
SO3
C2H5OH
MgF2
H2S
NH4Cl
Model shows an arrangement of positive and negative ions with larger - ions arranged around smaller + ions.
Which of the following correctly indicates whether the solid represented by the particulate model shown above conducts electricity and explains why or why not?
It conducts electricity because it is made of positive and negative ions.
It conducts electricity because it is made of particles of different sizes.
It does not conducts electricity because ions cannot move freely within the solid.
It does not conduct electricity because there are small spaces between the particles.
At 27oC five identical rigid 2.0 L vessels are filled with N2 and sealed. Four of the five vessels also contain a 0.050 mol sample of NaHCO3, NaBr, Cu, or I2. The volume taken up by the solids is negligible, and the initial pressure of N2in each vessel is 720 mmHg. All four vessels are heated to 127oC and allowed to reach a constant pressure.
The gas particles in the vessel 3 at 27oC are represented in the diagram shown. The lengths of the arrows represent the speeds of the particles. Which of the following diagrams best represents the particles when vessel 3 is heated to 127oC ?
The initial rate date in the table above were obtained for the reaction represented below. What is the experimental rate law for the reaction?
2 No + O2 --> NO2
Rate = k[BI][O2]
Rate = k[NO][O2]^2
Rate = k[NO]^2[O2]
Rate = k[NO]^2[O2]^2
C2H4 is reduced by H2 in the presence of a solid platinum catalyst as represented by the equation above. Factors that could affect the rate of the reaction include which of the following?
I. Changes in the partial pressure of H2
II. Changes in the particle size of the platinum catalyst
III. Changes in the temperature of the reaction system
III only
I and II only
I and III only
II and III only
I, II, and III
Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound?
It has the formula XZ2
It does not dissolve in water
It contains ionic bonds
It contains covalent bonds
The lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions largest? (Assume that the distance between the ions in each pair is equal to the sum of the ionic radii)
Na^+ and Cl^-
Ca^+ and Br^-
Mg^2+ and O^2-
Ca^2+ and O^2-
The atom that contains exactly two unpaired electrons
S
Ca
Ga
Sb
Br
When reaction 3 occurs, does the hybridization of the carbon atoms change>
Yes it changes from sp to sp^2
Yes it changes from sp to sp^3
es it changes from sp^2 to sp^3
No it does not change.
For element X represented above, which of the following is the most likely explanation for the large difference between the second and third ionization energies?
The effective nuclear charge decreases with successive ionization.
The shielding of outer electrons increases with successive ionizations.
The electron removed during the third ionization is, on average, much closer to the nucleus than the first two electrons removed were.
The ionic radius increases with successive ionization.
Which of the following best helps explain why an increase in temperature increases the rate of a chemical reaction?
At higher temperatures, reactions have a lower activation energy.
At higher temperatures, reactions have a higher activation energy.
At higher temperatures, every collision results in the formation of product.
At higher temperatures, high-energy collisions happen way more frequently,
The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum?
Nitrogen atoms have a half-filled p subshell.
There are more electron-electron repulsions in oxygen atoms than in nitrogen atoms.
Electrons in the p subshell of oxygen atoms provide more shielding than electrons in the p sub shell of nitrogen atoms.
Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
C2H4 + H2 --> C2H6
Which of the following will most likely increase the rate of the reaction represented above?
Decreasing the temperature of the reaction system
Adding a heterogenous catalyst to the reaction system
Increasing the volume of the reaction vessel using a piston
Removing some H2 from the reaction system,
Which of the following best helps to account for the fact that the F^- ion is smaller than the O^2- ion?
F^- has a larger nuclear mass than O^2- has
F^- has a larger nuclear charge than O^2- has
F^- has more electrons than O^2- has
F^- is more electronegative than O^2- is
F^- is more polarizable than O^2- is
Which of the molecules has the largest dipole moment
CO2
H2O
CH$
C2H4
A student was asked to formulate a hypothesis about what would happen if 100 mL of 0.1 M NaOH at 25 C was combined with 100 mL of 0.1 M MgCl2 at 25 C. Which of the following hypotheses indicates that the student thought a chemical change would occur.
The volume of the resulting solution will be equal to the sum of the volume of the original solutions
The mass of the resulting solution would be equal to the masses of the original solutions.
The resulting solution would contain a precipitate
The resulting solution will be clear
At standard temperature and pressure, a 0.50 mol sample of H2 gas and a separate 1.0 mol sample of O2 gas have the same
average molecular kinetic energy
average molecular speed
volume
effusion rate
density
At 27oC five identical rigid 2.0 L vessels are filled with N2 and sealed. Four of the five vessels also contain a 0.050 mol sample of NaHCO3, NaBr, Cu, or I2 as shown in the diagram. The volume taken up by the solids is negligible, and the initial pressure of N2 in each vessel is 720 mmHg. All four vessels are heated to 127oC and allowed to reach a constant pressure.
At 127oC, the pressure in vessel 1 is found to be higher than that in vessel 2. Which of the following reactions best accounts for the observation?
NaHCO3(s) --> Na(s) + HCO3(s)
NaHCO3(s) --> NaH(s) + CO3(s)
2NaHCO3(s) --> Na2CO3 (s) + CO2(g) + H2O(g)
2NaHCO3(s) + N2(g) --> 2NaNO3(s) + C2H2(g)
Which of the following molecules is best represented by two or more resonance forms
BeCl2
SO2
N2
O2
F2
