Chemistry Trivia Questions for College Students — page 2

Considering 0.1 M aqueous solutions of each of the following, which solution has the lowest pH?

• ANa3PO4
• BNa2CO3
• CNaCl
• DNa2S

What is the ratio of line intensities in the EPR spectrum of the t-Bu radical (CH3)3C•?

• A1:9:36:84:126:126:84:36:9:1
• B1:19:36:84:126:126:84:36:19:1
• C1:9:35:82:120:120:82:35:9:1
• D1:8:28:56:70:56:28:8:1

Which of the following is an n-type semiconductor?

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

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

Which of the following is the most common naturally-occurring form in which silicon is found?

• AFluoride
• BSulfide
• COxide
• DMetallic element

Of the following atoms, which has the lowest electron affinity?

• AF
• BO
• CSi
• DCa

The equation ΔH = ΔU + PΔV is applicable

• Aonly for constant temperature processes
• Bonly for constant volume processes
• Conly for constant pressure processes
• Dalways

The anhydride of Ba(OH)2 is

• ABaO
• BBa
• CBaOH
• DBaH2

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

Cobalt-60 is used in the radiation therapy of cancer and can be produced by bombardment of cobalt-59 with which of the following?

• AAlpha particles
• BX-rays
• CNeutrons
• DBeta particles

Which of the following statements about the lanthanide elements is NOT true?

• AAll of the lanthanide elements react with aqueous acid to liberate hydrogen.
• BThe atomic radii of the lanthanide elements increase across the period from La to Lu.
• CLanthanide complexes often have high coordination numbers (> 6).
• DThe most common oxidation state for the lanthanide elements is +3.

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

Which nuclide has an NMR frequency of 115.5 MHz in a 20.0 T magnetic field?

• A31P
• B17O
• C29Si
• D19F

3 Cl−(aq) + 4 CrO_4^2−(aq) + 23 H+(aq) → 3 HClO2(aq) + 4 Cr3+(aq) + 10 H2O(l). In the reaction shown above, Cl−(aq) behaves as

• Aa base
• Ban acid
• Ca catalyst
• Da reducing agent

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 magnetic moment of 205Tl?

• A0.827 x 10^-26 J T-1
• B0.717 x 10^-26 J T-1
• C[ɣ (205TI = 1.569 x 108 T-1 s-1, I = ½]
• D1.433 x 10^-26 J T-1

A silyl radical bearing an Si-H· fragment has a g value of 2.0033 and a pair of lines separated by 15.5 MHz. Express the splitting in units of mT, Gauss and cm-1.

• A15.5 MHz = 7.352 mT = 10.104 Gauss = 18.39 x 10^-4 cm-1
• B15.5 MHz = 0.553 mT = 5.530 Gauss = 5.17 x 10^-4 cm-1
• C15.5 MHz = 11.104 mT = 27.201 Gauss = 0.862 x 10^-4 cm-1
• D15.5 MHz = 1.55 mT = 0.562 Gauss = 31.0 x 10^-4 cm-1

Chlorofluorocarbons (CFCs) such as F3CCCl3 are implicated in the decomposition of stratospheric ozone. Which of the following methods would be best suited to measurement of trace amounts (sub-ppb) of CFCs in an air sample?

• AGas chromatographic separation of the air sample on a capillary column followed by flame ionization detection
• BGas chromatographic separation of the air sample on a capillary column followed by electron capture detection
• CConversion of the sample of the chlorinated compounds to chloride ions, followed by titration with Ag+
• DGas chromatographic separation of the air sample on a packed column followed by thermal conductivity detection

The number of allowed energy levels for the 55Mn nuclide are:

• A5
• B8
• C3
• D4

Which of the following is always true of a spontaneous process?

• AThe entropy of the system increases.
• BThe process does not involve any work.
• CThe total entropy of the system plus surroundings increases.
• DThe process is exothermic.

Redox enzyme catalysis involves the cyclic oxidation and reduction of metal ions that have at least two stable positive oxidation states. Which of the following groups of metals could be found at the active site of redox enzymes?

• ACu, Fe, Co
• BSr, Ga, Mg
• CZn, Ca, Ga
• DNa, Ba, Al

Which of the following types of spectroscopy is a light-scattering technique?

• AUltraviolet-visible
• BInfrared
• CRaman
• DNuclear magnetic resonance

Which of the following statements is not a reason why tetramethylsilane is used as a 1H chemical shift reference.

• AIts protons are quite strongly shielded.
• BIt dissolves in most organic solvents.
• CIts 1H spectrum is a singlet.
• DMost organic compounds do not contain silicon atoms.

Calculate the equilibrium polarization of 13C nuclei in a 20.0 T magnetic field at 300 K.

• A3.43 x 10^-5
• B4.11 x 10^-5
• C1.71 x 10^-5
• D10.8 x 10^-5

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−

On the basis of oxidation-reduction potential, which of the following is most likely to occur?

• APb(s) + Ca(NO3)2(aq) → Ca(s) + Pb(NO3)2(aq)
• BZn(s) + 2 Ag(NO3)(aq) → 2 Ag(s) + Zn(NO3)2(aq)
• CPb(s) + 2 LiNO3(aq) → 2 Li(s) + Pb(NO3)2(aq)
• DAl(s) + 3 NaNO3(aq) 3 Na(s) + Al(NO3)3(aq)

The strongest base in liquid ammonia is

• ANH2−
• BNH3
• CN2H4
• DNH4+

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.

Of the following ionic substances, which has the greatest lattice enthalpy?

• AMgO
• BNaCl
• CNaF
• DMgS

Suppose that the 13C nuclei in a molecule in a 600 MHz spectrometer can be 100% polarized (p = 1). If T1 = 5.0 s, how long does it take for p to reach a value equal to twice the thermal equilibrium polarization at 298 K?

• A[The polarization relaxes exponentially: p(t) = [p(0) - peq]exp(-t/T1) + peq.]
• B72.0 s
• C12.7 s
• D56.6 s

Which of the following is true for Br2 at standard temperature and pressure?

• AIt is a red-brown volatile liquid.
• BIt is a yellow metallic solid.
• CIt is a colorless volatile liquid.
• DIt is a colorless gas.

The Henry's law constant for CO2 dissolved in water at 25°C is 30.0 atm M^−1. The concentration of dissolved CO2 in a vessel pressurized with 2.0 atm of CO2 is

• A0.067 M
• B0.015 M
• C1.5 M
• D0.15 M

The X-band (9.5 GHz) EPR spectrum of a matrix isolated Na atom reveals four hyperfine lines with resonant field positions of 3074 G, 3174 G, 3274 G and 3374 G. Calculate the g value of the atom.

• Ag = 2.002
• Bg = 2.250
• Cg = 1.950
• Dg = 2.005

Estimate the β-hyperfine value for the cyclobutyl radical (C4H7•) assuming the radical is flat and the HCH angle is 115°.

• A27 G
• B4.6 mT
• C3.8 mT
• D5.4 mT

At 25°C, the maximum amount of PbI2 that can be dissolved in 1.00 L of pure water is 1.0 mmol. Assuming complete dissociation, the solubility product, K_sp, for lead iodide at 25°C is

• A1.0 × 10^−6
• B4.0 × 10^−9
• C1.0 × 10^−3
• D1.0 × 10^−9

Calculate the magnetic moment (μI) of a 13C nucleus.

• A1.1445 x 10^-28 J T-1
• B3.1445 x 10^-27 J T-1
• C6.1445 x 10^-27 J T-1
• D9.1445 x 10^-27 J T-1

When the following equation is balanced, which of the following is true? __ MnO4− + __ I− + __ H+ <-> __ Mn2+ + __ IO3− + __ H2O

• AThe I− : IO3− ratio is 3:1.
• BThe H+ : I− ratio is 2:1.
• CThe MnO4- : I- ratio is 6:5.
• DThe MnO4- : Mn2+ ratio is 3:1.

The T2 of an NMR line is 15 ms. Ignoring other sources of linebroadening, calculate its linewidth.

• A0.0471 Hz
• B42.4 Hz
• C66.7 Hz
• D21.2 Hz

Which of the following statements most accurately explains why the T1 of a nucleus is sometimes longer than its T2?

• AT1, unlike T2, is sensitive to very low-frequency molecular motions.
• BT2, unlike T1, is sensitive to very low-frequency molecular motions.
• CT2, unlike T1, is sensitive to molecular motions at the Larmor frequency.
• DT1, unlike T2, is sensitive to molecular motions at the Larmor frequency.

The solid-state structures of the principal allotropes of elemental boron are made up of which of the following structural units?

• AB4 tetrahedra
• BB6 octahedra
• CB8 cubes
• DB12 icosahedra

Predict the number of lines in the EPR spectrum of a solution of 13C-labelled methyl radical (13CH3•), assuming the lines do not overlap.

• A3
• B4
• C6
• D24

Calculate the polarization of a proton in a magnetic field of 335 mT and 10.5 T at 298 K.

• A6.345 x 10^-4 at 0.335 T; 9.871 x 10^-5 at 10.5 T
• B0.793 x 10^-4 at 0.335 T; 6.931 x 10^-7 at 10.5 T
• C1.148 x 10^-6 at 0.335 T; 3.598 x 10^-5 at 10.5 T
• D4.126 x 10^-3 at 0.335 T; 2.142 x 10^-6 at 10.5 T

Nitronyl nitroxides are stable radicals in which the unpaired electron is coupled to two equivalent nitrogen nuclei. How many lines will appear in the EPR spectrum of a solution of a rigid nitronyl nitroxide diradical with J << a?

• A5 lines
• B7 lines
• C3 lines
• D9 lines

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

A substance that is NOT generally considered to be a toxic pollutant in water is

• Acarbonic acid
• Bmercury
• Ca halogenated hydrocarbon
• Dlead

An electron and a proton are placed in a 1.0 T magnetic field at 300 K. What is the ratio of the equilibrium polarizations: |pe / pH| ?

• A[|ɣe| = 1.761 x 10^11 T^-1 s^-1]
• B658
• C820
• D329

Elements with partially filled 4f or 5f orbitals include all of the following EXCEPT

• ACu
• BAm
• CEu
• DGd