WorksheetsPractice MC 41-60
Total questions: 20
Worksheet time: 2hrs 40mins
N2 molecules absorb ultraviolet light but not visible light. I2 molecules absorb both visible and ultraviolet light. Which of the following statements explains the observations?
More energy is required to make N2 molecules vibrate than is required to make I2 molecules vibrate.
More energy is required to remove an electron from an I2 molecule than is required to remove an electron from a N2 molecule.
Visible light does not produce transitions between electronic energy levels in the N2 molecule but does produce transitions in the
I2 molecule.
The molecular mass of I2 is greater than the molecular mass of N2 .
To make Au stronger and harder, it is often alloyed with other metals, such as Cu and Ag. Consider two alloys, one of Au and Cu and one of Au and Ag, each with the same mole fraction of Au. If the Au/Cu alloy is harder than the Au/Ag alloy, then which of the following is the best explanation based on the information in the table above?
Cu has two common oxidation states, but Ag has only one.
Cu has a higher melting point than Au has, but Ag has a lower melting point than Au has.
Cu atoms are smaller than Ag atoms, thus they interfere more with the displacement of atoms in the alloy.
Cu atoms are less polarizable than are Au or Ag atoms, thus Cu has weaker interparticle forces.
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 subshell of nitrogen atoms.
Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
Nonane and 2,3,4-trifluoropentane have almost identical molar masses, but nonane has a significantly higher boiling point. Which of the following statements best helps explain this observation?
The C–F bond is easier to break than the C–H bond.
The C–F bond is more polar than the C–H bond.
The carbon chains are longer in nonane than they are in 2,3,4- trifluoropentane.
The carbon chains are farther apart in a sample of nonane than they are in 2,3,4-trifluoropentane.
Half-cell 1: strip of Al(s) in 1.00 M Al(NO3)3(aq)
Half-cell 2: strip of Cu(s) in 1.00 M Cu(NO3)2(aq)
Half-cell 3: strip of Fe(s) in 1.00 M Fe(NO3)2(aq)
What is the standard cell potential of galvanic cell Z?
0.26 V
0.78 V
2.34 V
3.22 V
Half-cell 1: strip of Al(s) in 1.00 M Al(NO3)3(aq)
Half-cell 2: strip of Cu(s) in 1.00 M Cu(NO3)2(aq)
Half-cell 3: strip of Fe(s) in 1.00 M Fe(NO3)2(aq)
In galvanic cells Y and Z, which of the following takes place in half-cell 3 ?
Reduction occurs in both cell Y and cell Z.
Oxidation occurs in both cell Y and cell Z.
Reduction occurs in cell Y, and oxidation occurs in cell Z.
Oxidation occurs in cell Y, and reduction occurs in cell Z.
Half-cell 1: strip of Al(s) in 1.00 M Al(NO3)3(aq)
Half-cell 2: strip of Cu(s) in 1.00 M Cu(NO3)2(aq)
Half-cell 3: strip of Fe(s) in 1.00 M Fe(NO3)2(aq)
If the half-cell containing 1.00 M Fe(NO3)2(aq) in galvanic cells Y and Z is replaced with a half-cell containing 5.00 M Fe(NO3)2(aq), what will be the effect on the cell voltage of the two galvanic cells?
The voltage will increase in both cells.
The voltage will decrease in both cells.
The voltage will increase in cell Y and decrease in cell Z.
The voltage will decrease in cell Y and increase in cell Z.
The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, chlorous, hydrochloric, lactic, and propanoic.
For which acid is the value of the acid dissociation constant, Ka, the smallest?
Acid 1
Acid 2
Acid 3
Acid 4
The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, chlorous, hydrochloric, lactic, and propanoic.
Which of the four acids listed in the table is hydrochloric acid?
Acid 1
Acid 2
Acid 3
Acid 4
The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, chlorous, hydrochloric, lactic, and propanoic.
Of the following species, which has the greatest concentration in a 1.0 M solution of acid 1 at equilibrium?
OH−
H3O+
Acid 1
The conjugate base of acid 1
The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, chlorous, hydrochloric, lactic, and propanoic.
If equal volumes of the four acids at a concentration of 0.50M are each titrated with a strong base, which will require the greatest volume of base to reach the equivalence point?
Acid 1
Acid 2
Acid 3
All the acids will require the same volume of base to reach the equivalence point.
The pH of solutions of four acids prepared at various concentrations were measured and recorded in the table above. The four acids are, in no particular order, chlorous, hydrochloric, lactic, and propanoic.
A 25 mL sample of a 1.0 M solution of acid 1 is mixed with 25mL of 0.50 M NaOH. Which of the following best explains what happens to the pH of the mixture when a few drops of 1.0 M HNO3 are added?
The pH of the mixture increases sharply, because HNO3 is a strong acid.
The pH of the mixture decreases sharply, because H3O+ ions were added.
The pH of the mixture stays about the same, because the conjugate base of acid 1 reacts with the added H3O+ ions.
The pH of the mixture stays about the same, because the OH− ions in the solution react with the added H3O+ ions.
Step 1: Cl(g) + O₃(g) → ClO(g) + O₂(g)
Step 2: ClO(g) + O(g) → Cl(g) + O₂(g)
A proposed mechanism for destruction of ozone gas in the stratosphere is represented above. Which of the following is evidence that the mechanism is occurring?
The presence of Cl(g) increases the rate of the overall reaction.
The presence of Cl(g) decreases the rate of the overall reaction.
The presence of Cl(g) increases the equilibrium constant of the overall reaction.
The presence of Cl(g) decreases the equilibrium constant of the overall reaction.
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 spaced farther apart in NaCl .
NaCl will have a higher boiling point than MgO because
the energy required to transfer electrons from the anion
to the cation is larger in NaCl than in MgO .
The table above shows the values of Ka for four weak acids. Which of the following pairs of chemical species, when combined in equimolar amounts, results in a buffer with a pH closest to 7.5 ?
HNO₂ and OH−
HC₃H₅O₂ and C₃H₅O₂−
HClO and ClO−
C₆H₅OH and C₆H₅O−
Beaker X and beaker Y each contain 1.0 L of solution, as shown above. A student combines the solutions by pouring them into a larger, previously empty beaker Z and observes the formation of a white precipitate. Assuming that volumes are additive, which of the following sets of solutions could be represented by the diagram above?
Beaker X 2.0 M AgNO₃
Beaker Y 2.0 M MgCl₂
Beaker Z 4.0 M Mg(NO₃)₂ and AgCl(s)
Beaker X 2.0 M AgNO₃
Beaker Y 2.0 M MgCl₂
Beaker Z 2.0 M Mg(NO₃)₂ and AgCl(s)
Beaker X 2.0 M AgNO₃
Beaker Y 1.0 M MgCl₂
Beaker Z 1.0 M Mg(NO₃)₂ and AgCl(s)
Beaker X 2.0 M AgNO₃
Beaker Y 1.0 M MgCl₂
Beaker Z 0.50 M Mg(NO₃)₂ and AgCl(s)
2 N₂O₅(g) → 4 NO₂(g) + O₂(g)
A sample of N₂O₅ was placed in an evacuated container, and the reaction represented above occurred. The value of N₂O₅, the partial pressure of N₂O₅(g), was measured during the reaction and recorded in the table below.
Which of the following correctly describes the reaction?
The decomposition of N₂O₅ is a zero-order reaction.
The decomposition of N₂O₅ is a first-order reaction.
The decomposition of N₂O₅ is a second-order reaction.
The overall reaction order is 3.
Based on periodic trends and the data in the table above, which of the following are the most probable values of the atomic radius and the first ionization energy for potassium, respectively?
242 pm, 633 kJ/mol
242 pm, 419 kJ/mol
120 pm, 633 kJ/mol
120 pm, 419 kJ/mol
The figure above shows that in solid hydrogen fluoride there are two different distances between H atoms and F atoms. Which of the following best accounts for the two different distances?
Accommodation of the necessary bond angles in the formation of the solid
Difference in strength between covalent bonds and intermolecular attractions
Different isotopes of fluorine present in the samples
Uneven repulsions among nonbonding electron pairs
COCl₂(g) ↔ CO(g) + Cl₂(g)
COCl₂(g) decomposes according to the equation above. When pure COCl₂(g) is injected into a rigid, previously evacuated flask at 690 K, the pressure in the flask is initially 1.0 atm. After the reaction reaches equilibrium at 690 K, the total pressure in the flask is 1.2 atm. What is the value of Kp for the reaction at 690 K?
0.040
0.050
0.80
1.0
