Understanding Measurement and Chemical Reactions: Exam Prep Guide
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CUNY Hunter College**We aren't endorsed by this school
Course
CHEM 102
Subject
Chemistry
Date
Dec 12, 2024
Pages
16
Uploaded by AgentOxide5694
Exam One1. The degree of agreement among several measurements of the same quantity is calledIt reflects the reproducibility of a given type of measurement.A. AccuracyB. ErrorC. PrecisionD. SignificanceE. Certainty2. The agreement of a particular value with the true value is calledA. AccuracyB. ErrorC. PrecisionD. SignificanceE. Certainty3. Convert 36.1 m3to cm3A. 3.61 x 105cm3B. 3.61 x 107cm3C. 3.61 x 103cm3D. 3.61 x 10-3cm3E. 3.61 x 10-5cm34. Which of the following has 61 neutrons, 47 protons, and 46 electrons?A.Pm6180B.Ag +47108C.Pd -47108D.Cd +47108E.Ag471085. A hypothetical element consists of two isotopes of masses 79.95 amu and 81.95 amu withabundances of 31.3% and 68.7%, respectively. What is the average atomic mass of this element?A. 80.95 amuB. 79.95 amuC. 80.6 amuD. 81.3 amuE. 81.95 amu6. What is the coefficient for oxygen when the following equation is balanced?NH3(g) + O2(g) → NO2(g) + H2O(g)A. 3B. 6C. 7D. 12
E. 147. A solid acid HX is mixed with water. Of the two possible solutions illustrated below, which ofthe following is true?A. In case I, HX is acting like a weak acid, and in case II, HX is acting like a strong acid.B. In case I, HX is acting like a strong acid, and in case II, HX is acting like a weakacid.C. In both cases, HX is acting like a strong acidD. In both cases, HX is acting like a weak acid.E. HX is not soluble in water8. In the reaction Zn + H2SO4 → ZnSO4 + H2, which, if any, element is oxidized?A. ZincB. HydrogenC. SulfurD. OxygenE. None of these9. Consider the following unbalanced oxidation-reduction reaction:Fe^2+ + Cl2 → Fe^3+ + ClIn the balanced equation, the number of electrons transferred is:A. 1B. 3C. 2D. 4E. None of these10. The acid equilibrium constant Ka is a measure of acid strength. Stronger acids have largerKa.A. TrueB. False11. The number 0.005,436 has how many significant figures?A. 7B. 3C. 4
D. 5E. 612. What is the volume of a 2.50 gram block of metal whose density is 6.72 grams per cubiccentimeter?A. 16.8 cubic centimetersB. 2.69 cubic centimetersC. 0.0595 cubic centimetersD. 0.372 cubic centimetersE. 1.60 cubic centimeters13. Nitric acid is a very important industrial chemical: 1.612 x 101 pounds of it were produced in1992. If the density of nitric acid is 12.53 pounds/gallon, what volume would be occupied by thisquantity? (1 gallon = 3.7854 liters)A. 7.646 x 101litersB. 8.388 x 109litersC. 1.287 x 109litersD. 5.336 x 1010 litersE. 4.870 x 109 liters14. Rutherford carried out experiments in which a beam of alpha particles was directed at a thinpiece of metal foil. From these experiments he concluded that:A. Electrons are massive particles.B. The positively charged parts of atoms are moving about with a velocity approaching thespeed of light.C. The positively charged parts of atoms are extremely small and extremely heavy particles.D. The diameter of an electron is approximately equal to that of the nucleus.E. Electrons travel in circular orbits around the nucleus.15. The neutral atoms of all of the isotopes of the same element haveA. Different numbers of protons.B. Equal numbers of neutrons.C. The same number of electrons.D. The same mass numbers.E. The same masses.16. How many moles of alanine, C3H7NO2, are there in 159 g of alanine?A. 1.42 x 104B. 1.78C. 0.992D. 0.560E. 3.3117. Which one of the samples contains the most atoms?A. 1 mol of CO2(g)B. 1 mol of UF6(g)C. 1 mol of CH COCH3(1)D. 1 mol of He(g)E. All contain the same number of atoms
18. Balance the following equation using minimum integral coefficients:NH3 + O2 → NO2 + H2OA. 1B. 4C. 3D. 7E. 519. Which one of the following statements is TRUE?A. One mole of any acid will ionize completely in aqueous solution to produce one mole ofH+ ions.B. Solutions of weak acids always have lower concentrations of H+ than solutions ofstrong acids.C. There are several common acids that are insoluble.D. All of the IA and IIA metal hydroxides are soluble.E. All weak acids are insoluble.20. Determine the oxidation number of carbon in K2C03A. 0B. +2C. +4D. -2E. Some other valueExam Two1. Given wavelength λ, frequency ν, and light speed c, the wavelength of light satisfies theformula,A. λ = 1/ c νB. λ= c+ νC. λ= c/νD. λ= ν/cE. λ= c- ν2. In an investigation of the electronic absorption spectrum of a particular element, it is foundthat a photon having λ = 500 nm provides just enough energy to promote an electron from thesecond quantum level to the third. From this information, we can deduceA. The difference in energies between n = 2 and n = 3B. The energy of the n = 3 levelC. The sum of the energies of n = 2 and n = 3D. The energy of the n = 2 levelE. None of these3. If n = 2, how many hydrogen spatial orbitals, having n =2, are possible?A. 3B. 4C. 2D. 8
E. 94. How many electrons in an atom can have the quantum numbers n = 2, l = 0?A. 2B. 5C. 10D. 18E. 65. Which of the following was not an elemental property we would have expected to be predictedby Mendeleev for as-yet-unknown elements?A. Electron configurationB. Atomic massC. DensityD. Boiling pointE. Chemical behavior6. Which of the following statements about quantum theory is incorrect?A. The energy and position of an electron cannot be determined simultaneously.B. Lower energy orbitals are filled with electrons before higher energy orbitals.C. When filling orbitals of equal energy, two electrons will occupy the same orbitalbefore filling a new orbital.D. No two electrons can have the same four quantum numbers.E. All of these are correct.7. Nitrogen has five valence electrons. Consider the following electron arrangementsa. ↑↓↑ ↑↑b. ↑↑↓↑↓c. ↑↑↑↑↑↑d. ↑↓↑ ↑e. ↑↓↑↓↑↑Which arrangement above represents the ground state for N?A. option aB. option bC. option cD. option dE. option e8. Which of the following statements is true?A. The first ionization potential of H is greater than that of He.B. The ionic radius of Fe3+ is larger than that of Fe+.C. The ionization energy of S2– is greater than that of Cl–.D. The atomic radius of Li is larger than that of Cs.E. All are false.9. The force between two bodies having opposite electric chargesA. Is a force of attractionB. Is a force of repulsion if the charges are negative, and one of attraction if they are positive
C. Increases as the bodies are moved further apartD. Is independent of the distance between themE. Is directly proportional to the distance between them10. Atoms having moderately unequal electronegativities are expected to forA. No bondsB. Polar covalent bondsC. Nonpolar covalent bondsD. Ionic bondsE. HH-covalent bonds11. Choose the compound with the most ionic bond.A. LiClB. KFC. NaC lD. LiFE. KCl12. Atoms with similar electronegativity values are expected to formA. No bondsB. Covalent bondsC. Triple bondsD. Ionic bondsE. None of these13. Which of the following bonds is most polar?A. C—OB. H—ClC. S—ClD. Br—BrE. They are all nonpolar.14. Which of the following statements is incorrect?A. Ionic bonding results from the transfer of electrons from one atom to another.B. Dipole moments result from the unequal distribution of electrons in a molecule.C. The electrons in a polar bond are found nearer to the more electronegative element.D. A molecule with very polar bonds can be nonpolar.E. Linear molecules cannot have a net dipole moment.15. As the number of bonds between two carbon atoms decreases, which one of the followingincreases?A. Number of electronsB. Bond energyC. Bond lengthD. All of theseE. None of these16. Given the following bond energies:C–C 347 kJ/molC=C 614 kJ/mol
C–O 358 kJ/molC=O799 kJ/molC–H 413 kJ/molO–H463 kJ/molO–O146 kJ/molestimate the magnitude of ΔE for the reaction H2O2 + CH3OH → H2CO + 2H2O.A. 245 kJB. 199 kJC. 105 kJD. 199 kJE. 345 kJ17. A triple bond occurs when two atoms share six electrons.A. TrueB. False18. In the Lewis structure for elemental nitrogen there is (are)A. A single bond between the nitrogensB. A double bond between the nitrogensC. A triple bond between the nitrogensD. Three unpaired electronsE. None of the above19. This molecule shows the smallest number of lone pairs in its Lewis structure.A. H2OB. CO2C. CH3ClD. C2H6E. All have zero lone pairs20. Which of the following molecules contains a triple bond?A. CO2B. N2C. H2OD. AllE. None21. The Lewis structure for CHCl3 has nine lone electron pairs.A. TrueB. False22. How many of the following molecules possess dipole moments? BH3, CH4, PCl5, H2O, H2A. 1B. 2C. 3D. 4E. 523. The molecular structure of OF2 is
A. PyramidalB. None of theseC. OctahedralD. Trigonal planarE. Bent24. The molecular structure of BrF6+ isA. PyramidalB. None of theseC. OctahedralD. Trigonal planarE. Bent25. The bond angles about the boron atom in the molecule, BH3, are about:All have zero lone pairs.A. 120B. 60C. 109D. 180E. 90Exam Three1. Ethylene, a planar molecule, contains two carbons and four hydrogens; choose those hybridsattached to the central atoms.A. Not hybridizedB. Sp hybridizedC. Sp2hybridizedD. Sp3hybridizedE. Dsp hybridized2. Choose below the best answer for a central atom with sp2hybridization:
B.3. For the following molecule,H O H HI II I IH-C-C-C=C-HIHchoose a false answer from the list below.A. There are 10 sigma and 2 pi bonds.B. C-2 is sp2hybridized with bond angles of 120°.C. Oxygen is sp3hybridized.D. This molecule contains 28 valence electrons.E. There are some H-C-H bond angles of about 109° in the molecule.4. Choose below the useful hybrids for borane (one boron & 3 hydrogens).A. SpB. Sp2C. Sp3D. Dsp3E. D2sp5. Look for a pair of pi bonds in,
A. C2H4B. C3H8C. C2H2D. C2H6E. CH46. For ethane (2 carbons and 6 hydrogens) the useful hybrids are,A. SpB. Sp2C. Sp3D. Dsp3E. D2sp37. One constructs pi bonds by,A. Overlap of two s orbitalsB. Overlap of an s orbital and a p orbitalC. Overlap of two p orbitals along their axes,D. Sidewise overlap of two parallel p orbitalsE. Sidewise overlap of two s orbitals8. An atom in a molecule presents sp3hybrids, thus creating,A. 4 pi bondsB. 3 pi bonds and 1 sigma bondC. 2 pi bonds and 2 sigma bondsD. 1 pi bond and 3 sigma bondsE. 4 pi bonds9. For a central atom bonding to the far corners of a tetrahedron the best hybrids are d'sp orbitals.A. TrueB. False10. For Boron trifloride the best hybrids would be sp. 4 EDA. TrueB. False11. The shortest bond below would be in,A. C2H2B. C2H4C. C2H6D. C2Cl4E. B & D12. Conservation of spatial dimensions: Two atoms of the same chemical name each have 4atomic orbitalswhich overlap between the pair of atoms to form how many molecular orbitals?A. 1B. 4C. 8D. 16E. None of these
13. There is a correlation between bond order and bond strengthA. TrueB. False14. As bond order increases, the magnitude of bond energy___ and the bond length___A. Increases, increasesB. Decreases, decreasesC. Increases, decreasesD. Decreases, increasesE. More information is needed to answer this15. The presence of a nonzero magnetic field in a molecule suggests that,I. The substance can have both paired and unpaired electronsII. The bond order must not be a whole numberIII. It can be determined by inverse VSEPRIV. It must be an ionA. I,IIB. I,II, IVC. II, IIID. I onlyE. all are correct16. Whether or not there is a magnetic field associated with diatomic oxygen is indicated by,A. The Lewis structure of O2B. ResonanceC. A violation of the octet ruleD. The molecular orbital diagram for O2E. Hybridization of atomic orbitals in O217. As expected for diatomic neon the bond order of magnitudeA. 0B. ½C. 1D. 1 ½E. 218. One expects increased bonding by addition of one electron to diatomic hydrogen.A. TrueB. False19. Benzene is a flat ring with 6 C's and 6 H's and pi-bonding electrons equal in number to,A. 12B. 30C. 3D. 6E. 1820. Consider two diagrams below: Decreasing by one electron in the diagram on the rightincreases bonding, but the same action in the diagram on the left decreases bonding.
A. TrueB. FalseExam Four1. Boyle's law states that:A. Equal amounts of gasses occupy the same volume at constant temperature and pressure.B. The volume of a fixed amount of gas is inversely proportional to its pressure atconstant temperature.C. The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin atconstant pressure.D. The total pressure of a mixture of gasses is the simple sum of the partial pressure of all of thegaseous compounds.E. The rates of effusion of gasses are inversely proportional to the square roots of their molarmasses.2. You are holding four identical balloons each containing 10.0 g of a different gas. The balloonContaining which gas is the smallest balloon?A. H2B. HeC. NeD. O2E. All have the same3. Which conditions of P, T, and n, respectively, are least ideal?A. High P, high T, high nB. Low P, low T, low nC. High P, low T, high n
D. Low P, high T, high nE. Low P, high T, low n4. For an ideal gas, which pairs of variables are inversely proportional to each other (if all otherfactors remain constant)?A. V and TB. T and nC. n and VD. P and T5. Which of the following is the best qualitative reaper P versus molar mass of a 1-g sample ondifferent gasses at constant volume and temperature?A. The speed of each atom of helium is 926 m/s.B. The r m s speed of the He and the Ar atoms are the same.C. The average kinetic energy of the two samples are equal.D. All of the above are true.E. None of the above are true.6. What would happen to the average kinetic energy of the molecules of a gas sample if thetemperature of the sample decreased from 40°C to 20°C?A. It would double.B. It would increase.C. It would decrease.D. It would become half its value.E. Two of these.7. Consider the following containers, one with helium at 27°C and the other with argon at 27°C.Which of the following statements are true?A. The speed of each atom of helium is 926 m/s.B. The r m s speed of the He and the Ar atoms are the same.C. The average kinetic energy of the two samples are equal.D. All of the above are true.E. None of the above are true.8. The pressure of an ideal gas will ___ when the volume is decreased and will ___ when theabsolute temperature is decreased.A. Increase…increase
B. Increase…decreaseC. Decrease…increaseD. Decrease…decreaseThe Van der Waal equation for one mole of a gas has the mathematical form(P +a / V)(V-b) =RT:9. The value of the Van der Waal coefficient 'a' decreases with decrease inA. PressureB. Molecular volumeC. Intermolecular forcesD. Temperature10. Inclusion of two properties in the kinetic molecular theory of ideal gases, that cause idealbehavior, are inter-particle forces & finite volume of gas particles.A. TrueB. False11. A gas absorbs 0.0 J of heat and then performs 30.7 J of work. The change in internal energyof the gas isA. 61.4 JB. 30.7JC. -61.4 JD. -30.7JE. None of these12. Which of the following statements correctly describes the signs of q and w for the followingexothermic process at P = 1 atm and T = 370 K?H2O(g) → H2O(1)A. q and w are negative.B. q 1s positive, w is negativeC. q is negative, w is positiveD. q and w are both positive.E. q and w are both zero.13. Which of the following statements is correct?A. The internal energy of a system increases when more work is done by the system thanheat was flowing into the system.B. The internal energy of a system decreases when work is done on the system and heat isflowing into the system.C. The system does work on the surroundings when an ideal gas expands against aconstant external pressure.D. All statements are true.E. All statements are false.14. According to the first law of thermodynamics, ∆E =4 q + 4 w, the energy of the universe isconstant. Does this mean that AE is always equal to zero?A. Yes, ∆E = 0 at all times, which is why q =-w.B. No, ∆E does not always equal zero, but this is only due to factors like friction and heat.
C. No, ∆E does not always equal zero because it refers to the system's internalenergy, which is affected by heat and work.D. No, ∆E never equals zero because work is always being done on the system or by thesystemE. No, ∆E never equals zero because energy is always flowing between the system andsurroundings.15. Of energy, work, enthalpy, and heat, how many are state functions?A. 0B. 1C. 2D. 3E. 416. For the reaction H2O(1) → H20(g) at 298 K and 1.0 atm. is more positive than AE by 2.5kJ/mol. This quantity of energy can be considered to beA. The heat flow required to maintain a constant temperatureB. Work done in pushing back the atmosphereC. The difference in the H-O bond energy in H2O(l) compared to H2O(g)D. The value of ∆H itself17. Two metals of equal mass with different heat capacities are subjected to the same amount ofheat. Which undergoes the smallest change in temperature?A. The metal with the higher heat capacity.B. The metal with the lower heat capacity.C. Both undergo the same change in temperatureD. You need to know the initial temperatures of the metals.E. You need to know which metals you have.18. Consider the following specific heats of metals.MetalSpecific heatZinc0.387J/(g°C)Magnesium1.02 J/(g°C)Iron0.450 J/(g°C)Silver0.237J/(g°C)Lead0.127J/(g°C)If the same amount of heat is added to 25.0 glof each of the metals, which are all at the sameinitial temperature, which metal will have the highest temperature?A. ZincB. MagnesiumC. IronD. SilverE. Lead19. Consider the following processes:3B→2C + D-125(½)A→B150
E + A →D350Calculate ∆H for B→ E + 2CA. 325 kJ/molB. 525 kJ/molC. -175 kJ/molD. - 325 kJ/molE. None of these20. Which of the Following does not have a standard enthalpy of formation equal to 2ero at253°C and 1.0 atm?A. F2 (g)B. Al (s)C. H2O (l)D. H2(g)E. They all have a standard enthalpy equal to zero.