Chemistry Test #4

Choose the INCORRECT statement. A) A strip of metal in a solution of ions of that metal is an electrode potential. B) Oxidation is the loss if electrons. C) Electrons are transferred in oxidation-reduction reactions. D) A salt bridge maintains electrical contact between two half cells. E) Reduction is the gain of electrons.

A) A strip of metal in a solution of ions of that metal is an electrode potential.

Choose the INCORRECT statement. A) Fission is the combining of small nuclei into a larger nucleus. B) Control rods absorb neutrons. C) Water is a good moderator, it slows down neutrons. D) Breeder reactors generate new fuel as well as electricity. E) Thermal neutrons induce more fission reactions than energetic neutrons.

A) Fission is the combining of small nuclei into a larger nucleus.

In a sealed container, the rate of dissolving is equal to the rate of crystallization. Therefore we would expect: A) G = 0 B) G < 0 C) S = 0 D) G > 0 E) must know H to determine

A) G = 0

The maximum quantity of energy available for useful work is: A) Gibbs energy B) the entropy C) constant D) the internal energy E) the enthalpy

A) Gibbs energy

Nuclear binding energy is: I) the energy liberated when forming a nucleus II) related to "lost" mass by the relationship 1 amu = 28.4 MeV III) related to "lost" mass by the relationship 1 amu = 931.5 MeV IV) the force which holds the 3 atomic particles together

A) I and III

Which of the following statements are true? I) Liquids have more entropy than their solids. II) Solutions have more entropy than the solids dissolved. III) Gases and their liquids have equal entropy. IV) Gases have less entropy than their solids. V) Entropy of a substance increases as its temperature increases

A) I), II), and V)

Radiation can be detected as it interacts with matter by the use of: I) photographic film II) a bubble chamber III) Geiger-Muller counter

A) I, II, III

Choose the INCORRECT statement. A) If G = 0, the process is spontaneous. B) If G > 0, the process is nonspontaneous. C) If G < 0, the process is spontaneous. D) One form of the second law of thermodynamics is all spontaneous processes produce an increase in the entropy of the universe. E) Gibbs energy is defined by: G = H - TS.

A) If G = 0, the process is spontaneous.

Which of the following statements concerning alpha decay is INCORRECT? A) It has great penetrating power, but little ionizing power. B) It involves nuclides with atomic number larger than 83 and mass number larger than 200. C) The alpha particle is made up of two protons and two neutrons. D) It often leaves the nucleus in an excited state. E) The atomic number decreases by two.

A) It has great penetrating power, but little ionizing power.

Choose the INCORRECT statement. A) Keq is independent of temperature. B) In a Keq expression, the activity of a solution is replaced by its molarity. C) In a thermodynamic equilibrium constant expression, the activity of a gas is replaced by its partial pressure in atmosphere. D) If G = 0, the process is at equilibrium. E)Thevan'tHoffequationisln K2/K1 = H°/R (1/ T1 - 1/T2) .

A) Keq is independent of temperature.

The lithium-ion battery is based on A) Li+/Li couple B) Co(III)/Co(IV) couple C) both Li+/Li and Co3+/Co2+ D) Co3+/Co2+ couple E) both Li+/Li and Co(III)/Co(IV) E° = -0.125 V E° = -0.763 V C) -0.888 V

A) Li+/Li couple

Choose the INCORRECT statement. A) Radiation causes no harm to the human body. B) Radiation kills cancer cells more easily than normal cells. C) Bubble chambers detect radiation by the ionization trail left by the radiation. D) Alpha particles are less penetrating than beta particles. E) Geiger-Muller counters detect radiation by the ionization caused in the gas in the counter.

A) Radiation causes no harm to the human body.

Choose the INCORRECT statement. A) Reversing a half reaction makes it a reduction potential. B) Each electrochemical cell consists of a reduction half cell and an oxidation half cell. C) When a half reaction is reversed, the sign of the potential is changed. D) A voltaic cell is also called a battery. E) The potential difference of a cell is the voltage of the cell.

A) Reversing a half reaction makes it a reduction potential.

In a galvanic cell, oxidation occurs at the: A) anode B) salt bridge C) cathode D) in cathodic space E) electrolyte

A) anode

The following reaction is exothermic. 2N2O(g) 2N2(g) + O2(g) This means the reaction: A) is not spontaneous at any temperature B) will be spontaneous only at high temperature C) will be spontaneous only at low temperatures D) will be spontaneous at all temperatures

A) is not spontaneous at any temperature

There have been two ways of making transuranium elements: heavy-atom bombardment and: A) neutron bombardment B) photon bombardment C) beta bombardment D) gamma bombardment E) positron bombardment

A) neutron bombardment

Glass electrodes are used for direct measurement of: A) pH B) pKa C) pKw D) Q E) Ksp

A) pH

The following reaction is endothermic. 2NH3(g) N2(g) + 3H2(g) This means the reaction: A) will be spontaneous at high temperature B) is spontaneous at all temperatures C) is not spontaneous at any temperature D) will be spontaneous at low temperature

A) will be spontaneous at high temperature

Which statement below is correct? A) Breeder reactors are able to convert fissile nuclides into fertile ones, thus "breeding" more fuel. B) 238 U requires energetic neutrons in order to undergo fission and subsequently produces 239 Pu. C) Fission reactions with light nuclei, such as helium are easily controlled but do not produce as much energy as with heavy nuclei. D) In order for fusion to be sustained, the critical mass must be exceeded. E) In a pressurized water reactor, cadmium metal usually acts as the moderator.

B) 238 U requires energetic neutrons in order to undergo fission and subsequently produces 239 Pu.

The nuclear binding energy for cobalt-59 is the energy released when: A) iron-56 and 2 protons form cobalt-59 B) 27 protons and 32 neutrons form cobalt-59 C) cobalt-58 and 1 neutron form cobalt -59 D) 27 protons and 27 neutrons form cobalt-59

B) 27 protons and 32 neutrons form cobalt-59

The normal melting and boiling points of SO2 are 198 and 263 K, respectively. For a plot of the standard molar entropy of SO2 versus temperature, which of the following is INCORRECT? A) S° increases with increasing temperature. B) At 263 K, S° is constant. C) At 198 K, S° increases by the value of Sfusion. D) S° equals zero at 0 K.

B) At 263 K, S° is constant.

Choose the INCORRECT statement. A) A single vertical line separates phases in a cell diagram. B) Electrolytic cells are cells where electron flow is caused by spontaneous reactions. C) A voltaic cell is a galvanic cell. D) Voltaic cells produce an electron flow. E) A double vertical line separates half cells in a cell diagram.

B) Electrolytic cells are cells where electron flow is caused by spontaneous reactions.

Which of the following combinations of signs for H and S will always result in a reaction being nonspontaneous? A) H-, S+ B) H+, S- C) H-, S- D) H+, S+ E) cannot determine without temperature

B) H+, S-

Which of the following quantities for an element has a value of zero in the standard state? I) H°f II) G°f III) S°

B) I and II

Find correct statements. I) A spontaneous process is a process that occurs in a system left to itself. II) A nonspontaneous process will not occur unless some external force is applied. III) Ifareactionisspontaneous,thereverseisalsospontaneous. IV) Only spontaneous processes occur naturally. V) Entropy is inversely proportional to the degree of randomness.

B) I), II), and IV)

Choose the correct statement. A) All radiations emitted by radioactive nuclides consist of charged, high energy particles. B) Instability leading to decay by alpha particle emission is found mostly in nuclides of very large mass number. C) Decay by beta emission is confined to nuclides of very low mass number. D) Ejection of an electron by a nuclide results in a nuclide of next lower mass number. E) Many alpha and beta emissions are followed by gamma emissions.

B) Instability leading to decay by alpha particle emission is found mostly in nuclides of very large mass number.

Choose the INCORRECT statement. A) One mole of hydrogen gas requires 2 Faradays. B) One Faraday of charge will plate out two moles of Cu from a solution of CuSO4(aq). C) One Faraday of charge will release 35.5 g of Cl2 in the electrolysis of a chloride solution. D) One mole of hydrogen ions will have a positive charge of one Faraday. E) One mole of electrons has a charge of l Faraday.

B) One Faraday of charge will plate out two moles of Cu from a solution of CuSO4(aq).

Choose the INCORRECT statement. A) The standard cell potential is the potential difference between two half cells. B) SHE stands for Standard Helium Electrodes. C) E°cell is the standard cell potential. D) E° is the standard electrode potential. E) The standard electrode potential is the reduction potential of a half cell.

B) SHE stands for Standard Helium Electrodes.

Choose the INCORRECT statement. A) Radioactive decay is a first-order process. B) The half-life is the length of time for all atoms of an isotope to decay. C) Bi-209 has the highest mass number and atomic number of any stable isotope. D) The radioactive decay law is A = N. E) Wood can be dated by radiocarbon dating.

B) The half-life is the length of time for all atoms of an isotope to decay.

Choose the INCORRECT statement. A) S° = ( S°) products - ( S°) reactants. B) The third law of thermodynamics states that the entropy of a pure crystal at 298 K is zero. C) The activity of pure liquids or pure solids is 1. D) G° = -RT ln Keq. E) G° = H° - TS°.

B) The third law of thermodynamics states that the entropy of a pure crystal at 298 K is zero.

In a zinc-lead cell the reaction is: Pb2++ZnPb+Zn2+ E°=0.637V Which of the following statements about this cell is FALSE? A) The lead electrode is positively charged. B) The zinc electrode is the cathode. C) The actual cell voltage is less than +0.637 volts because of concentration polarization and possible other factors. D) The shorthand notation is Zn Zn2+ Pb2+ Pb E) The reaction will go in the direction indicated.

B) The zinc electrode is the cathode.

The fact that the entropies of vaporization for liquids which exhibit hydrogen bonding are greater 3) than the 87 J/(mol · K) which is expected of non-polar liquids is an exception to: A) the Clausius-Clapyeron Rule B) Trouton's Rule C) the Third Law of Thermodynamics D) the Second Law of Thermodynamics E) the Gibb's Energy Rule

B) Trouton's Rule

There have been two ways of making transuranium elements: neutron bombardment and: A) beta bombardment B) heavy-atom bombardment C) gamma bombardment D) positron bombardment E) photon bombardment

B) heavy-atom bombardment

If the voltage of an electrochemical cell is negative then the cell reaction is: A) slow B) nonspontaneous C) exothermic D) fast E) spontaneous

B) nonspontaneous

Choose the INCORRECT completion of the following sentence: "In the electrolysis of water... A) ...the volume of hydrogen produced is twice the volume of oxygen produced." B) ...electrical energy must be supplied continuously because it is an endothermic reaction." C) ...oxygen is evolved at the cathode." D) ....one mole of H2 is produced for each two moles of electrons." E) ...a direct current must be used."

C) ...oxygen is evolved at the cathode."

Choose the correct statement based on the following oxidation potentials. 60) 61) Mg/Mg2+ +2.37 v Fe/Fe2+ +0.44 v Cu/Cu2+ -0.34 v Ag/Ag+ -0.80 v Zn/Zn2+ +0.76 v Sn/Sn2+ A) Fe will displace Zn2+ from solution +0.14 v B) Mg will not displace Zn2+ from solution C) Fe will displace H+ from solution D) Cu will displace Sn2+ from solution E) Sn will displace Fe2+ from solution

C) Fe will displace H+ from solution

Choose the INCORRECT statement A) Fusion is not now used to produce electricity commercially. B) Fusion is the basis of the hydrogen bomb. C) Fusion is the splitting of a nucleus into two smaller nuclei. D) Fusion can produce an almost unlimited amount of energy. E) Fusion is a reaction that occurs on the sun.

C) Fusion is the splitting of a nucleus into two smaller nuclei.

Which of the following are commonly used as alternate standard electrodes: I) Ag(s) | AgCl(s) | Cl- (1.0 M) II) Hg(l) | HgCl2(s) | Cl- (1.0 M) III) Ag(s) | AgCl(s) | Cl- (0.1 M) IV) Hg(l) | Hg2Cl2(s) | Cl- (1.0 M V) Hg(s) | Hg2Cl2(s) | Cl- (1.0 M)

C) I) and IV)

Which of the following quantities is generally independent of temperature? I) H II) S III) G

C) III only

Which of the following best expresses the increased degree of randomness associated with melting and sublimation, respectively? A) Sfus = 9.0 J/mol-K, Ssub = -144.3 J/mol-K B) Sfus = 144.3 J/mol-K, Ssub = 9.0 J/mol-K C) Sfus = 9.0 J/mol-K, Ssub = 144.3 J/mol-K D) Sfus - Ssub = 0 E) H for both processes is zero

C) Sfus = 9.0 J/mol-K, Ssub = 144.3 J/mol-K

Which of the following relations is true for the molar entropy of sublimation of a substance? A) Ssub < Svaporization B) Ssub = Sfusion - Svaporization C) Ssub = Sfusion + Svaporization D) Ssub < (Sfusion + Svaporization)

C) Ssub = Sfusion + Svaporization

For the vaporization of water in an open system at 25°C and 1 atm, which of the following is correct? A) The reaction is enthalpy driven. B) G°rxn = 0 C) The reaction is entropy driven. D) The reaction is not spontaneous.

C) The reaction is entropy driven.

Choose the INCORRECT statement. A) Reversing a cell reaction changes the sign of Ecell. B) The work available in a cell = -zFEcell. C) When Ecell < 0, the reaction is spontaneous. D) When Ecell = 0, the reaction is at equilibrium. E) G° = -zFE°cell

C) When Ecell < 0, the reaction is spontaneous.

Which of the following instruments would be least suitable for detecting particles given off in 101) radioactive decay? A) film B) Geiger counter C) electron microscope D) bubble or cloud chamber E) Geiger-Muller counter

C) electron microscope

Which of the following would have the greatest penetrating power through matter? A) alpha particles B) positron particles C) gamma rays D) beta particles E) protons

C) gamma rays

The unit of radiation which is equivalent to 0.010 J/kg of matter is the: A) MeV B) roentgen C) rad D) rem E) curie

C) rad

If G < 0 for a reaction, then the reaction is said to be: A) fast B) exothermic C) spontaneous D) endothermic E) reversible

C) spontaneous

The Gibbs energy change for a reaction is -298 kJ. The reaction is therefore: A) nonspontaneous B) endothermic C) spontaneous D) irreversible E) exothermic

C) spontaneous

The change in Gibbs energy of a reaction: A) depends on the standard state chosen B) = H + TS C) tells us if the reaction is spontaneous or not D) = work E) predicts speed

C) tells us if the reaction is spontaneous or not

A spontaneous process: A) is never endothermic. B) requires an external action in order to begin reacting. C) will continue on its own once begun. D) will happen quickly. E) releases large amounts of energy.

C) will continue on its own once begun.

Choose the INCORRECT statement. A) Secondary batteries' cell reaction can be reversed. B) Cells can be joined in series to increase the total voltage. C) Primary batteries' cell reactions cannot be reversed. D) A primary battery is recharged by passing electricity through the battery. E) A concentration cell consists of half cells with identical electrodes but different ion concentrations.

D) A primary battery is recharged by passing electricity through the battery.

In the cell Fe2+ Fe3+ Cu2+ Cu which will increase the cell voltage the most? A) Halve [Fe2+]. B) Halve [Cu2+]. C) Double [Cu2+]. D) Double [Fe2+]. E) Cut Cu electrode in half.

D) Double [Fe2+].

Choose the INCORRECT statement. A) A cathode is where reduction occurs. B) The anode is on the left in a cell diagram. C) A cell diagram is a symbolic way to show cell components. D) Half cells in a cell diagram are separated by a single vertical line. E) An anode is where oxidation occurs.

D) Half cells in a cell diagram are separated by a single vertical line.

Which of the following are true for alpha particles? I) particles are equivalent to 2 1 p+ 2 1 n. 10 II) decay decreases the atomic number by four. III) particlesaredeflectedmorestronglythane-bymagneticfields,butintheoppositedirection. IV) particles are easily stopped as they strike matter.

D) I and IV

Indicate the statement(s) which are true for the process: Al+3(aq) + 3 OH-(aq) Al(OH)3(s) if it occurs in a closed container I) S increases because the final molecule is more complicated. II) Entropy decreases because the product is in the solid phase. III) Thetwoionsachieveahighdegreeoforderastheycrystalize,thereforeSispositive. IV) Entropy of the system is unchanged because the system is sealed and at a constant temperature

D) II only

Choose the INCORRECT statement. A) Rust is a form of corrosion. B) Metals can be protected by cathodic protection. C) Cathodic protection is attaching a more active metal to the protected metal. D) The active metal is called a sacrificial cathode. E) Corrosion of metals is an oxidation reduction process.

D) The active metal is called a sacrificial cathode.

Choose the INCORRECT statement about coupled reactions. A) The usual reason to couple reactions is to produce an overall spontaneous reaction. B) The reaction added to a nonspontaneous reaction needs to be more spontaneous than the original reaction is nonspontaneous. C) One of the coupled reactions has a negative G, the other a positive G. D) The usual practice of coupling reactions is to join two nonspontaneous reactions. E) The reaction added to a nonspontaneous reaction needs to be spontaneous.

D) The usual practice of coupling reactions is to join two nonspontaneous reactions.

The most massive particle is: A) positron B) gamma C) beta D) alpha E) neutron

D) alpha

An isotope which has too high a neutron-proton ratio can gain stability by: A) K-capture B) alpha emission C) gamma emission D) beta emission E) proton emission

D) beta emission

An employee at a chemical laboratory studying radioisotopes would wear a badge to keep a check 90) on the amount of radiation to which he is exposed. This radiation dosage would be measured in the unit: A) curie B) Joules C) Joules per kilogram D) rem E) rad

D) rem

Radioactive decay is: A) a process with a large activation energy B) a second-order process C) a zero-order process D) temperature independent

D) temperature independent

Which of the following is FALSE? A) A - decay is accompanied by the emission of a neutrino. B) An e- capture converts a proton to a neutron in the nucleus of an atom. C) A - particle is essentially an e- originating from the nucleus. D) A + decay converts a proton to a neutron in the nucleus of an atom. E) A - decay results in a decrease in atomic number.

E) A - decay results in a decrease in atomic number.

Choose the INCORRECT statement. A) Gamma rays are emitted from a nucleus in an excited state. B) Radioactivity is the emission of ionizing radiation. C) An alpha particle is the nucleus of a helium-4 atom. D) A positron is like a beta particle but with a positive charge. E) A beta particle is a neutron.

E) A beta particle is a neutron.

Choose the INCORRECT statement. A) Particular ratios of neutrons to protons are more stable. B) Even numbers of protons and neutrons are more stable. C) Magic numbers are certain numbers of protons and/or neutrons which are especially stable. D) The nuclear binding energy is the mass changed to energy that holds the nucleus together. E) All isotopes below Bi are stable.

E) All isotopes below Bi are stable.

Choose the INCORRECT statement. A) The electromotive force (emf) is the cell potential. B) An electrode is often a strip of metal. C) An electrode in a solution of its ions is a half cell. D) The cell potential is the potential difference between the half cells. E) An electrochemical cell is a half cell.

E) An electrochemical cell is a half cell.

Choose the INCORRECT statement. A) Radiation works against cancer because cancer cells are more easily damaged than normal cells. B) Protons, x-rays, and neutrons can also be used against cancer cells. C) Ionizing radiation tends to kill all cells. D) Cancer can be treated with gamma rays. E) Cancer cannot be caused by ionizing radiation.

E) Cancer cannot be caused by ionizing radiation.

Choose the INCORRECT statement. A) Electrons dislodged from an atom or molecule by alpha or beta particles are called primary electrons. B) Radiation exposes photographic film the same as light. C) A moderator slows down neutrons. D) An isotope that will fission when hit by a neutron is said to be fertile. E) Control rods absorb energy to control the fission reaction.

E) Control rods absorb energy to control the fission reaction.

An electrolysis is carried out by passing an electric current through a solution of copper sulfate using inert electrodes. This causes: A) H2 to form at the negative electrode B) Cu to plate out on the anode C) oxygen to form on the negative electrode D) sulfur to form on the positive electrode E) Cu to plate out on the negative electrode

E) Cu to plate out on the negative electrode

Choose the correct statements concerning entropy. I) As two gasses mix, S is positive. II) Entropy is a thermodynamic property related to the degree of disorder. III) As temperature in a gas decreases, S is positive. IV) Molecules in the liquid state have higher entropy than molecules in the gaseous state.

E) I and II

A reaction is spontaneous if: I) G is a negative value II) both enthalpy and entropy increase III) HisnegativeandSispositive IV) bothenthalpyandentropydecrease V) H is positive and S is negative

E) I and III

Half-life is: 111) I) the time for a sample to decay completely. II) constant for a given radioisotope. III) the time required for half of a sample to decay. IV) inversely proportional to the decay constant.

E) II,III,andIV

Which of the following types of nuclear decay result in a decrease in nuclear charge? I) alpha emission II) beta emission III) position emission IV) electron-capture

E) III and IV

The observation that a 30 g sample of C-14 has a decay rate faster than that of a 20 g sample of 86) C-14 would be consistent with the: A) Mass-Rate Principle B) Mass-decay ratio C) Half-Life Principle D) Disintegration Rule E) Radioactive decay law

E) Radioactive decay law

Most periodic tables indicate the elements for which all isotopes are radioactive. Which pair of elements with atomic number less than 83 have only radioactive isotopes? A) C and K B) Pb and At C) Tc and Cd D) K and Pm E) Tc and Pm

E) Tc and Pm

For an exothermic reaction to be nonspontaneous at high temperatures, the enthalpy must be 25) ________ while the entropy is ________. A) positive, negative B) a relatively large negative value, positive C) a very large negative value, also negative D) positive, also positive E) a relatively small negative value, also negative

E) a relatively small negative value, also negative

The most highly charged particle is: A) beta B) gamma C) positron D) neutron E) alpha

E) alpha

Transuranium elements can be produced by bombarding nuclei with: A) alpha particles B) neutrons C) other nuclei D) positrons E) neutrons and/or other nuclei

E) neutrons and/or other nuclei

If G is positive for a certain reaction, then: A) one would need to know the Kelvin temperature to determine spontaneity. B) there would be no reaction possible for a negative value. C) the reaction is spontaneous. D) the system is in equilibrium. E) the reverse of the reaction is spontaneous.

E) the reverse of the reaction is spontaneous.

Choose the INCORRECT statement. A) There is no difference in physical properties between isotopes. B) Industrial catalysts can be followed by a tracer such as 192Ir. C) The thyroid gland can be studied by the use of radioactive iodine. D) Radioactive 32P as a phosphate can be used to trace the uptake of phosphorus in plants. E) The mechanism of a chemical reaction can be followed by a radioactive tracer such as 35S.

There is no difference in physical properties between isotopes.