Chemistry Trivia Questions for Students — page 3

Which of the following may need to be balanced using the ion-electron method ?

• ABaCl2 + Al2(SO4)3 → AlCl3 + BaSO4
• BC2H2(g) + N2O(g) → CO2(g) + H2O(g) + N2(g)
• CH+ + OH- → H2O
• DNaOH + H3PO4 → Na2HPO4 + H2O

A sample of liquid NH3 is brought to its boiling point. Which of the following occurs during the boiling process?

• AThe N-H bonds within the NH3 molecules break apart.
• BThe amount of energy within the system remains constant.
• CThe overall temperature of the solution rises as the NH3 molecules speed up.
• DThe hydrogen bonds holding separate NH3 molecules together break apart.

Under which conditions will a real gas most closely behave as an ideal gas?

• AHigh temperature and high pressure
• BLow temperature and low pressure
• CHigh temperature and low pressure
• DHigh volume and high temperature

What is the empirical formula of a compound that is 51.9% carbon, 4.86% hydrogen, and 43.2% bromine

• AC12H22Br
• BC6H4Br3
• CC8H9Br
• DC7H5Br

The electrolysis of molten magnesium bromide is expected to produce

• Amagnesium at the anode and bromine at the cathode
• Bbromine at the anode and hydrogen at the cathode
• Cmagnesium at the cathode and oxygen at the anode
• Dmagnesium at the cathode and bromine at the anode

What is the molecular mass of a gas that has a density of 2.05 g/L at 26.0 °C and 722 torr?

• A46.7 g/mol
• B2876 g/mol
• C53.0 g/mol
• D4.67 g/mol

Which of the following is incorrectly named?

• AFe(NO3)3 iron(III) nitrate
• BAlBr3 aluminum tribromide
• CCaCl2 calcium chloride
• DK2Cr2O7 potassium dichromate

A sealed, rigid container contains three gases: 28.0 g of nitrogen, 40.0 g of argon, and 36.0 g of water vapor. If the total pressure exerted by the gases is 2.0 atm, what is the partial pressure of the nitrogen?

• A0.50 atm
• B0.40 atm
• C2.0 atm
• D0.33 atm

Which of the following has an octet of electrons around the central atom?

• ASF6
• BNH4+
• CBF3
• DPF5

The dimerization of NO2(g) to N2O4(g) is an endothermic process. Which of the following will, according to Le Châtelier's principle, increase the amount of N2O4 in a reaction vessel?

• ADecreasing the temperature
• BAdding a selective catalyst
• CMaking the reaction vessel smaller
• DIncreasing the size of the reaction vessel

A student has a liter of a 0.100 M solution of a strong acid. To prepare a buffer, this should be mixed with

• Aa strong acid
• Ba weak acid
• Ca strong base
• Da weak base

Which of the following is a radioactive element?

• AAl
• BAm
• CCr
• DNa

Of the following oxo acids, which is predicted to be the strongest acid?

• AHClO3
• BHIO
• CHClO
• DHBrO

2Ag+(aq) + Fe(s) → 2Ag(s) + Fe2+(aq) Which of the following would cause an increase in potential in the voltaic cell described by the above reaction?

• AAdding more Fe(s)
• BIncreasing [Fe2+]
• CDecreasing [Fe2+]
• DRemoving some Fe(s)

Which of the following processes is an irreversible reaction?

• ACH4(g) + O2(g) → CO2(g) + H2O(l)
• BHCN(aq) + H2O(l) → CN-(aq) + H3O+(aq)
• C2Ag+(aq) + Ti(s) → 2Ag(s) + Ti2+(aq)
• DAl(NO3)3(s) → Al3+(aq) + 3NO3-(aq)

The photoelectron spectrum of carbon has three equally sized peaks. What peak is at the lowest energy?

• AThe 2s peak has the lowest energy.
• BThe 1s peak has the lowest energy.
• CThe 2p peak has the lowest energy.
• DThe 1p peak has the lowest energy.

The rate law for the reaction of 2 A + B → 2 P is

• Ak[A]2[B]
• B[A]2[B]
• Cimpossible to determine without experimental data
• Dsecond order with respect to A

A first-order reaction has a half-life of 34 minutes. What is the rate constant for this reaction?

• A2.04 × 10^-2 s-1
• B3.4 × 10^-4 s-1
• C2.9 × 10^-1 min-1
• D34 min

Twenty-five milligrams of sucrose (C12H22O11) are dissolved in enough water to make 1.00 liter of solution. What is the molality of the solution?

• A1.36
• B7.3 × 10^-5
• C73.1
• D7.31 × 10^-2

What is the pH of a solution prepared by dissolving 0.1665 mole of hypochlorous acid (HClO) in enough water to make 500 mL of solution? The Ka is 3.0 × 10^-4

• A2
• B1
• C1.76
• D5.4 × 10^-3

Fluorine has a normal boiling point of 85 K, and chlorine boils at 239 K. The Cl2 molecule is much larger than F2 (atomic radius is 99 pm for chlorine and is 64 pm for fluorine). Which is the best reason for the large difference in boiling points?

• AThe Cl2 electron clouds are much more polarizable than the F2 electron clouds, resulting in much stronger London forces.
• BChlorine has a higher dipole moment than fluorine.
• CThe mass of chlorine is much greater than the mass of fluorine.
• DThe intramolecular bonds in Cl2 are much weaker than those in F2.

The rate law may be written using stoichiometric coefficients for which of the following?

• ASolubility reactions
• BElementary processes
• CPrecipitation reactions
• DAcid-base reactions

Helium effuses through a pinhole 5.33 times faster than an unknown gas. That gas is most likely

• ACH4
• BC8H18
• CC5H12
• DCO2

The bond length between any two nonmetal atoms is achieved under which of the following conditions?

• AThe point at which the attractive and repulsive forces between the two atoms are equal
• BWhere the energy of interaction between the atoms is at its minimum value
• CThe closest point at which a valence electron from one atom can transfer to the other atom
• DWhere the nuclei of each atom exhibits the strongest attraction to the electrons of the other atom

In which of the following is the negative end of the bond written last?

• AO—S
• BBr—N
• CN—C
• DP—Cl

Which of the following molecules is a strong electrolyte when dissolved in water?

• APCl5
• BCH3COOH
• CHC2H3O2
• DHBr

The first ionization energy of sodium is 496 kJ/mol, and its atomic radius is 186 pm.

• A240 pm, 1200 kJ/mol
• B160 pm, 737 kJ/mol
• C235 pm, 523 kJ/mol
• D86 pm, 398 kJ/mol

4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) This reaction will experience a rate increase by the addition of a cataylst such as platinum. Which of the following best explains why?

• AThe catalyst increases the frequency of collisions that occur at the proper orientation in the reactant molecules.
• BThe catalyst increases the activation energy for the reaction.
• CThe catalyst introduces a new reaction mechanism for the reaction.
• DThe catalyst increases the overall frequency of collisions in the reactant molecules.

The subatomic particle with the most penetrating ability is

• Aa neutron
• Ba proton
• Can alpha particle
• Da beta particle

Which of the following correctly lists the individual intermolecular attractive forces from the strongest to the weakest?

• AInduced dipole < dipole-dipole < hydrogen bond
• BInduced dipole < hydrogen bond < dipole-dipole
• CDipole-dipole < hydrogen bond < induced dipole
• DHydrogen bond < dipole-dipole < induced dipole

A new compound is synthesized and found to be a monoprotic acid with a molar mass of 248 g/mol. When 0.0050 mol of this acid are dissolved in 0.500 L of water, the pH is measured as 3.89. What is the pKa of this acid?

• A5.78
• B3.89
• C2.33
• D7.78

Which following pair of substances can be used to make a buffer solution?

• AHIO3 and KClO3
• BHC2H3O2 and KC2H3O2
• CNaCl and HCl
• DNaBr and KBr

Which pair of reactants will have no net ionic equation (that is, all the ions cancel)?

• ANa2SO3 + FeCl2
• BNH4I + Pb(NO3)2
• CCaCl2 + MnSO4
• DKOH + HClO4

Which of the following is the strongest Brønsted-Lowry acid?

• AHBrO3
• BHBrO2
• CHBrO
• DHBrO4

Carbon exists in various forms called allotropes. Which of the following is not an allotrope of carbon?

• Agraphite
• Bdiamond
• Csoot
• Dbuckminsterfullerene

Changing which of the following will change the numerical value of the equilibrium constant?

• AThe pressure of products
• BThe total mass of the chemicals present
• CThe temperature
• DThe pressure of reactants

Identify the Brønsted-Lowry conjugate acid-base pair in the following list.

• AH3O+ and OH-
• BH3PO4 and H3PO3
• CSO32- and SO22-
• DHC2H3O2 and C2H3O2-

Atoms of four elements are examined: carbon, nitrogen, neon, and sulfur. Which element would have a photoelectron spectra in which the peak representing electrons with the lowest ionization energy would be three times higher than all other peaks?

• ASulfur
• BNitrogen
• CCarbon
• DNeon

Chemists often ascribe the macroscopic properties of solids to the underlying microscopic structure. Silicon carbide is almost as hard and brittle as diamond. The solid state structure of silicon carbide is often described as

• Aa molecular crystal
• Ba metallic crystal
• Can ionic crystal
• Da covalent or network crystal

Each resonance form of the nitrate ion, NO3-, has how many sigma and how many pi bonds?

• A1 sigma and 2 pi
• B1 sigma and 1 pi
• C2 sigma and 1 pi
• D3 sigma and 1 pi

If 1.0 g of rubidium and 1.0 g of bromine are reacted, what will be left in measurable amounts (more than 0.10 mg) in the reaction vessel?

• ARbBr only
• BRbBr and Rb only
• CRbBr, Rb, and Br2
• DRbBr and Br2 only

Sulfurous acid is a weak acid, while sulfuric acid is a much stronger acid because

• Athe sulfur in sulfuric acid is more electronegative than the sulfur in sulfurous acid
• Bsulfuric acid has more oxygen atoms in its formula
• Cthe O–H bonds in sulfuric acid are much weaker than those in sulfurous acid
• Dsulfurous acid has its hydrogen atoms bound directly to the sulfur atom

Three half-lives after an isotope is prepared,

• A25% of the isotope is left
• B12.5% of the isotope decayed
• C12.5% of the isotope is left
• D25% of the isotope decayed

Your supervisor asks you to determine the enthalpy of a certain chemical reaction. Which would you do?

• AUse a photoelectron spectrometer to measure the energies of all atoms in the compounds, and use Hess's law to add them.
• BUse a bomb calorimeter to measure the heat of the reaction.
• CUse a solution calorimeter such as a coffee-cup calorimeter to measure the heat.
• DMeasure the ΔS and the ΔG for the reaction, and calculate the ΔH from the Gibbs free energy equation.

The molecule with a tetrahedral shape is

• APCl4F
• BCBr4
• CCO2
• DBF3

Based on periodic relationships, the concepts related to bond strength, and the concept relating bond strength to acid strength, which of the following correctly predicts the strength of binary acids from strongest to weakest?

• AH2S > H2Se > H2O
• BH2Se > H2O > H2S
• CH2Se > H2S > H2O
• DH2O < H2S < H2Se

Which of the following pairs of ions would make the best buffer with a basic pH? Ka for HC3H2O2 = 1.75 × 10^-5. Ka for HPO42- = 4.8 × 10^-13.

• AHPO42- and NaH2PO4-
• BH2SO4 and H2PO4
• CNaOH and HC2H3O2
• DHC3H2O2 and NaC3H2O2

The functional group that represents an organic acid is written as (Note: R represents the rest of the molecule)

• AROH
• BRCl
• CRCOOH
• DRCHO

Which of the following pairs of substances would make a good buffer solution?

• AHF(aq) and NH3(aq)
• BH2SO4(aq) and LiOH(aq)
• CHC2H3O2(aq) and NaC2H3O2(aq)
• DHCl(aq) and KCl(aq)

A mechanism is a sequence of elementary reactions that add up to the overall reaction stoichiometry. A substance that is produced in one elementary reaction and consumed in another is called

• Aan intermediate
• Ba reactant
• Ca complex
• Da catalyst