Chemistry Trivia Questions — page 4

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 single line is seen in the 31P spectrum of a solution of sodium phosphate. The 31P chemical shifts of H2PO4‾ and HPO42– are 3.42 ppm and 5.82 ppm respectively. What is the chemical shift when the pH of the solution equals the pKa of H2PO4‾?

• A3.98 ppm
• B3.41 ppm
• C4.62 ppm
• D4.33 ppm

Dissolving one mole of each of the following compounds in water results in solutions with different pH values. Under those conditions, which of the following acids will have the highest percentage ionization?

• AH2S
• BHNO2
• CH3PO4
• DHClO4

Which of the following is considered a metalloid?

• ACr
• BS
• CMn
• DSi

The Rydberg equation v = R_H(1/n_1^2 - 1/n_2^2) accurately predicts the UV-visible emission spectrum of the hydrogen atom. A form of the Rydberg equation may also be used to predict the UV-visible emission for all of the following EXCEPT

• Adeuterium atom, D
• Bhelium cation, He+
• Ctritium atom, T
• Dhydride ion, H−

From the solubility rules, which of the following is true?

• AAll ammonium-containing compounds are soluble
• BAll chlorides, bromides, and iodides are soluble
• CAll sulfates are soluble
• DAll hydroxides are soluble

The strongest base in liquid ammonia is

• ANH2−
• BNH3
• CN2H4
• DNH4+

The 1H spectrum of a mixture of dimethylsulphoxide (DMSO) and acetonitrile (AN) contains lines with relative intensities α and 3α, respectively. What is the ratio of the two concentrations, [DMSO]:[AN]?

• A1:1
• B1:3
• C1:6
• D2:3

Which of the following substances has an asymmetrical molecular structure?

• APCl5
• BCO2
• CBF3
• DSF4

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

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

• Agraphite
• Bdiamond
• Csoot
• Dbuckminsterfullerene

Examining data obtained from mass spectrometry supports which of the following?

• AIonization energy trends within the periodic table
• BThe common oxidation states of elements
• CThe existence of isotopes
• DAtomic size trends within the periodic table

Which of the following is expected to have the largest bond polarity?

• AC–N
• BP–F
• CC–B
• DS–O

What is the molarity of a sodium hydroxide solution that requires 42.6 mL of 0.108 M HCl to neutralize 40.0 mL of the base?

• A0.0641 M
• B0.115 M
• C0.400 mol/L
• D1.64 M

Which of the following molecules cannot hydrogen bond with molecules identical to itself but can hydrogen bond with one of the molecules above or below it in the following responses?

• ACH3CH2CHO
• BCH3CH2COOH
• CC6H5CHO
• DCH3CH2OH

The 1H Larmor frequency of benzene exceeds that of trifluoroacetic acid by 1.656 kHz on a 400 MHz spectrometer. The 1H chemical shift of benzene is 7.16 ppm. What is the chemical shift of trifluoroacetic acid?

• A10.56 ppm
• B11.30 ppm
• C5.03 ppm
• D3.02 ppm

During a chemical reaction, NO(g) gets reduced and no nitrogen-containing compound is oxidized. Which of the following is a possible product of this reaction?

• ANO2(g)
• BNO3-(aq)
• CNO2-(aq)
• DN2(g)

The rate of a chemical reaction is determined by

• Athe reaction vessel pressure
• Bthe intermediates formed in the first step
• Cthe equilibrium constant
• Dthe rate-determining or slow step of the mechanism

Of the following compounds, which has the lowest melting point?

• AHCl
• BAgCl
• CCCl4
• DCaCl2

Calculate the relative occupancies of the α and β spin energy levels for a radical species with g = 2.05, at L- and W-band frequencies (take TS = 300 K).

• ANα/Nβ = 0.9850 at L-band; Nα/Nβ = 0.9809 at W-band
• BNα/Nβ = 0.9800 at L-band; Nα/Nβ = 0.9509 at W-band
• CNα/Nβ = 0.9910 at L-band; Nα/Nβ = 0.9709 at W-band
• DNα/Nβ = 0.9950 at L-band; Nα/Nβ = 0.9609 at W-band

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

The amplitude of a free induction decay drops to 25% of its initial intensity after 1.0 s. Assuming exponential relaxation and Ω = 0, determine the value of T2.

• A0.750 s
• B1.386 s
• C0.721 s
• D1.661 s

Of the following solutions, which will have the highest ionic strength? (Assume complete dissociation.)

• A0.050 M CaCl2
• B0.100 M NaCl
• C0.050 M AlCl3
• D0.100 M HCl

Using fundamental trends in electronegativity and bond strength, which of the following should be the strongest acid?

• AHBr
• BH2S
• CH2O
• DHI

Which of the following experimental observations were explained by Planck's quantum theory?

• ATemperature dependence of reaction rates
• BEmission spectra of diatomic molecules
• CElectron diffraction patterns
• DBlackbody radiation curves

SO2Cl2 → SO2(g) + Cl2(g) At 600 K, SO2Cl2 will decompose to form sulfur dioxide and chlorine gas via the above equation. If the reaction is found to be first order overall, which of the following will cause an increase in the half life of SO2Cl2?

• ADecreasing the overall pressure in the container
• BIncreasing the initial concentration of SO2Cl2
• CIncreasing the temperature at which the reaction occurs
• DNone of these will increase the half life

Which of the following is an n-type semiconductor?

• ADiamond
• BSilicon
• CArsenic-doped silicon
• DSilicon carbide

Consider the Lewis structures for the following molecules: CO2, CO32-, NO2-, and NO3-. Which molecules are best represented by multiple resonance structures?

• ACO2 and CO32-
• BCO32-, NO2- and NO3-
• CCO32- and NO3-
• DNO2- and NO3-

All of the following ions have the same electron configuration except

• ARb+
• BSr2+
• CAs5+
• DSe2-

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

• AO—S
• BBr—N
• CN—C
• DP—Cl

Calculate the magnetic field responsible for the polarization of 2.5 x 10^-6 for 13C at 298 K.

• A2.9 T
• B0.5 T
• C1.2 T
• D100 T

How many milliliters of 0.250 M KOH does it take to neutralize completely 50.0 mL of 0.150 M H3PO4?

• A270 mL
• B30.0 mL
• C90.0 mL
• D27 mL

The Pauli exclusion principle states that

• Ano two electrons can have the same four quantum numbers
• Bno two electrons can occupy separate orbitals
• Cno two electrons can pair up if there is an empty orbital available
• Dno two electrons with the same spin can occupy an orbital

Atoms of four elements are examined: carbon, nitrogen, neon, and sulfur. Atoms of which element are most likely to form a structure with the formula XF6 (where X is one of the four atoms)?

• ANeon
• BNitrogen
• CCarbon
• DSulfur

The +1 oxidation state is more stable than the +3 oxidation state for which group 13 element?

• AB
• BAl
• CIn
• DTl

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

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

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

Which would be the easiest way to burn an iron nail?

• AGrind the nail into very small, dust-sized particles, and spray them into a flame
• BUse the method in (A), but use an oxyacetylene torch to reach a higher temperature.
• CHold an iron nail with crucible tongs, and heat strongly in the flame of a Bunsen burner.
• DDissolve the nail in acid to make the oxide.

Which is the easiest way to burn a silver coin?

• AUse the method in (A), but use an oxyacetylene torch to reach a higher temperature.
• BGrind the silver coin into very small, dust-sized particles, and spray the particles into a Bunsen burner flame.
• CDissolve the silver coin in acid, precipitate the hydroxide, and heat in a Bunsen burner flame to make the oxide.
• DHold the silver coin with crucible tongs, and heat strongly in the flame of a Bunsen burner.

Predict the hyperfine value for the EPR spectrum of fully deuteriated benzene radical anion C6D6•-.

• A0.58 G
• B0.375 mT
• C2.35 mT
• D3.75 G

A PO3- radical produces a pair of lines separated by 280 MHz with giso = 2.005. Calculate the expected resonant field positions of both lines in the X-band EPR spectrum (ν = 9.5 GHz).

• ABres for mI = -½ = 325.0 mT; Bres for mI = +½ = 335.0 mT
• BBres for mI = -½ = 0.218 mT; Bres for mI = +½ = 0.418 mT.
• CBres for mI = -½ = 333.5 mT; Bres for mI = +½ = 343.5 mT.
• DBres for mI = -½ = 123.5 mT; Bres for mI = +½ = 124.5 mT.

What is the maximum number of phases that can be at equilibrium with each other in a three component mixture?

• A4
• B2
• C3
• D5

What is the general relationship between temperature and entropy for diatomic gases?

• AIt depends on the specific gas and the strength of the intermolecular forces between individual molecules.
• BThey are completely independent of each other; temperature has no effect on entropy.
• CThere is an inverse relationship, because at higher temperatures substances are more likely to be in a gaseous state.
• DThere is a direct relationship, because at higher temperatures there is an increase in energy dispersal.

Chlorine gas reacts most readily with

• Atoluene
• Bethanoic acid
• Cethane
• Dethylene

Which of the following statements most accurately explains why the 1H spectrum of 12CHCl3 is a singlet?

• AThe molecule is not rigid.
• BBoth 35Cl and 37Cl have electric quadrupole moments.
• CThe hydrogen atom undergoes rapid intermolecular exchange.
• DBoth 35Cl and 37Cl have I = 0.

The most massive subatomic particle is the

• Abeta particle
• Bproton
• Cneutron
• Dalpha particle

Magnesium has an atomic radius of 160 pm and a first ionization energy of 737 kJ. Based on periodic trends and the data given above, what are the most probable values for the ionization energy and atomic radius of sodium?

• A186 pm, 898 kJ/mol
• B186 pm, 496 kJ/mol
• C147 pm, 523 kJ/mol
• D135 pm, 523 kJ/mol

NH4+(aq) + NO2- (aq) → N2(g) + 2H2O(l) Increasing the temperature of the above reaction will increase the rate of reaction. Which of the following is NOT a reason that increased temperature increases reaction rate?

• AA greater distribution of reactant molecules will have high velocities.
• BThe number of collisions between reactant molecules will increase.
• CAlternate reaction pathways become available at higher temperatures.
• DThe reactants will be more likely to overcome the activation energy.

0.0025 mol of a weak, monoprotic acid is dissolved in 0.250 L of distilled water. The pH was then measured as 4.26. What is the pKa of this weak acid?

• A7.92
• B4.26
• C8.52
• D6.52

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)