CHEM 1202 Chapter : SP17 1202 Session 3 The First Law Of Thermodynamics Part 3 S I Edition

For which system below would quantum effects be leastnoticeable?

-The collision of two N₂ molecules in a gas, whichchanges the rotational energy of both

-Polarization of the electron density of ethanol resulting inexcitation of vibrational motions

-An electron-sized particle moving in a 1 m³ box asthe temperature decreases by 10 degrees

-A hydrogen atom being struck by a UV photon

We have dealt with two different ensembles, canonical andmicrocanonical. Which of the following statements is inaccurateregarding these ensembles?

-The canonical ensemble is always considered as a subset of alarger reservoir, which acts as the surroundings.

-The microcanonical ensemble is defined to have constant energy,volume, and composition.

-The microcanonical ensemble is a smaller subset of microstatesof the canonical ensemble.

-The canonical ensemble is generally more useful than themicrocanonical for chemical processes.

Which statement below is most correct regarding the partitionfunction of an ensemble?

-For a given temperature, the high-energy contributions to thepartition function are more heavily weighted.

-Once a partition function is defined in a specific ensemble, itis valid in all other ensembles.

-It tells us the numerical order of the energy levels for agiven system.

-It provides a measure of the energy levels available to asystem at a given temperature.

Consider a cup-carrier from your favorite take-out restaurant.The carrier can hold four cups, and you have to place two cups (onelarge, one small) into the carrier, with no preference forposition. How many microstates can you form with two cups in thefour spaces?

-12

-8

-16

-6

Boltzmann's definition of the entropy was a breakthrough inunderstanding statistical thermodynamics. What is the bestdefinition of Boltzmann's entropy?

-The Boltzmann entropy is a count of the total distinctmicrostates in a system.

-The Boltzmann entropy is a measure of the randomness of anensemble.

-The Boltzmann entropy is a count of the accessible energylevels at a given temperature.

-The Boltzmann entropy is a measure of the useful work availablein an ensemble.

Our canonical ensemble was defined such that the temperature,volume, and number of particles were each held constant. In termsof the Legendre transform, which thermodynamic potential isfundamental in the canonical ensemble?

-The Helmholtz energy

-The internal energy

-The Gibbs energy

-The enthalpy

The equipartition principle can be used to estimate the constantvolume heat capacities of gases. Under which circumstances wouldthe full equipartition heat capacity most closelyapproximate the measured value of C_V?

-A sample of N₂ gas at 373K

-A sample of propane gas (C₃H₈) at roomtemperature

-A sample of water vapor at 373K

-A sample of Br₂ vapor at room temperature

Which factor below does not contribute to the rotationalpartition function of a molecule?

-The rotational quantum number

-The nuclear and electronic spin states

-The rotational constant(s)

-The temperature of the molecule

We were able to reduce the vibrational partition function froman infinite series to a function of a single exponential, but onlyapproximately. Which approximation below was NOT used?

-We assumed that the vibrational energy can be expressed asv?_e.

-We assumed that the energy levels were close enough to allowintegration instead of summation.

-We assumed that the vibrational motion is purely harmonic.

-We assumed that the separations are relatively small, due tohigh temperature or lower vibrational constant.

The derived partition function for an ideal gas depends on allof the physical parameters listed below except for which one?

-Molecular symmetry

-The temperature of the molecules

-The volume of the sample

-Mass of the molecules

Deriving the translational partition function is more involvedthan deriving the rotational and vibrational partition functions.Which statement below is NOT a reason for this?

-There are so many possible translational energy levels, thatthe integral does not converge to a finite value.

-The integral of translational states for a single particle mustbe taken over a 6-dimensional hypervolume.

-The degeneracy of translational states is not obvious becausethey lie so close in energy.

-Translational degrees of freedom involve interactions betweenall molecules in the sample, whereas rotations and vibrations donot.

The connection between the Equipartition Principle and thetranslational partition functions helped to demonstrate that thetemperature of a system depends on the easily excited degrees offreedom. Why should this be true?

-In systems with easily excited degrees of freedom, a change inthe entropy requires energy changes on the order of thermalenergy.

-In systems with easily excited degrees of freedom, smallincreases in the pressure make excited states more accessible,

increasing the temperature.

-In systems with easily excited degrees of freedom, thepotential energy is no longer dependent on the temperature of thesystem.

-In systems with easily excited degrees of freedom, thermalenergy is sufficient to allow one to treat the energy levels as acontinuum.

The connection between the Maxwell-Boltzmann distribution andthe translational partition function allowed us to betterunderstand the distribution of speeds. Which statement below is NOTa consequence of the translational partition function?

-The population of the lowest speeds is very small.

-The pressure of the gas increases as the velocityincreases.

-An increase in the temperature will result in shifting thedistribution to higher energies.

-The population of the highest speeds is very small.

When dealing with quantum energy levels, there are severalimportant factors to consider. Which concept below is NOT importantto quantum energy levels?

-The set of quantum numbers

-Degeneracy

-The deBroglie wavelength

-The ground state

The equation Mg + HCl MgCl2 + H2 can be balanced by _____.

A) Changing the coefficient of Mg to 2

B) Changing the coefficient of HCl to 2

C) Changing the coefficient of MgCl2 to 12 .

D) Changing MgCl2 to MgCl

E) Changing H2 to H

In the reaction below, how many molecules of water can be made from 38 molecules of C6H12O6?

C6H12O6 + 6O2  6H2O + 6CO2 A) 38
B) 6
C) 144

D) 228 E) 44

In the chemical reaction H2SO4 + 2NaOH Na2SO4 + 2H2O, the coefficient of sodium sulfate is _____.
A) 0
B) 1

C) 2 D) 3 E) 4

H2CO3 CO2 + H2O is an example of which type of reaction?

A) Substitution

B) Combination

C) Combustion

D) Decomposition

E) Formation

In the reaction H2 + F2  2 HF, which of the following is true?

A) H2 is reduced

B) H2 is the oxidizing agent

C) F2 is reduced

D) HF is called the reducing agent

E) HF is called the oxidizing agent

Page 1

Ascorbic acid (C6H8O6) acts as an antioxidant by being oxidized to _____. A) C6H8O6
B) C6H8O8
C) C4H9O7

D) C6H6O4 E) C6H6O6

During anaerobic metabolism pyruvic acid is converted to _____.

A) lactic acid

B) citric acid

C) oxalic acid

D) acetic acid

E) nitric acid

Reduction of CH3 = CH3 by hydrogen yields _____.

A) 2CH4

B) CH2 = CH2

C) CH3CHO

D) C2H6

E) CH3OH

Which of the following is not considered to be a form of reduction?

A) Gain of a hydrogen ion

B) Gain of electrons

C) Loss of an oxygen ion

D) Gain of negative charge

E) Gain of a sodium ion

Consider the reaction:
Au(s) + 3HNO3(aq) + 4HCl(aq)  HAuCl4(aq) + 3NO2(g) + 3H2O(l), how many Au atoms will react with 996 molecules of HCl?
A) 1992
B) 996
C) 498
D) 249
E) 336

Page 2

Oxidation of CH3CHO gives _____. A) CH3COOH

B) C2H6
C) C2H5OH D) H2C=CO E) CH3OH

Three moles of (NH4)2Fe(SO4)2·6H2O contains _____ moles of H2O.

A) 3

B) 6

C) 9

D) 12

E) 18

How many moles of hydrogen atoms are present in 27 grams of H2O?

A) Approximately one

B) Approximately one and a half

C) Approximately two

D) Approximately two and a half

E) Approximately three

Five
atoms of nitrogen?

A) 140.07 u

B) 28.014 u

C) 14.007 u

D) 280.14 u

E) 42.021 u

What is the molar mass of MgCO3?

A) 56.928 g/mol

B) 71.173 g/mol

C) 85.755 g/mol

D) 84.313 g/mol

E) 36.312 g/mol

moles of nitrogen molecules have a mass of 140.07 g. What is the mass of 10

Page 3

Consider the formation of ammonium chloride given by the equation:
NH3 + HCl  NH4Cl. How many grams of HCl would fully react with 76.43 moles of ammonia?
A) 1302
B) 2787
C) 2709
D) 4088
E) 4071

In the reaction 2P + 5Cl2  2PCl5, how many moles of atomic chlorine need to be reacted to form 525 g of PCl5?

A) B) C) D) E)

18. 1 Pa A)

B) C) D) E)

1.00 3.15 2.00 12.6 6.30

= _____ 1 atm
1 torr
1 J/s

1 N/m2 1 kJ/m

If a sample of gas has an initial pressure of 2.36 atm and an initial volume of 10.7 L, what is the final pressure if the volume is reduced to 4.09 L? Assume that the amount and the temperature of the gas remain constant.

A) 103 atm

B) 6.17 atm

C) 0.902 atm

D) 43.8 atm

E) 18.5 atm

A gas sample at 40°C has an initial volume of 40.0 L. What is its volume if the temperature is changed to 120°C? Assume that the pressure and the amount of the gas remain constant.

A) 1.99 L

B) 8.13 L

C) 50.2 L

D) 31.9 L

E) 123L

Page 4

Three moles of (NH4)2Fe(SO4)2·6H2O contains _____ moles of hydrogen atoms.

A) 4

B) 6

C) 20

D) 60

E) 100

How many moles of oxygen atoms would be present in 3.65 moles of Na2SO4?

A) 13.56

B) 3.65

C) 7.30

D) 10.95

E) 14.60

How many moles of NaCl are present in 20.0 g of NaCl?

A) 58.4

B) 1.01

C) 29.2

D) 0.342

E) 0. 0143

How many moles of oxygen atoms are present in one mol of (C2H5COO)2Ca?

A) 1

B) 2

C) 3

D) 4

E) 5

Codeine (C18H21NO3) is a painkiller. What is the molar mass of codeine? A) 195.60

B) 299.37 C) 227.30 D) 211.43 E) 313.35

Page 5

In the reaction H2SO4 + 2NaOH  Na2SO4 + 2H2O, the number of moles of H2O that can be produced from 10 moles of NaOH is _____.
A) 2
B) 3

C) 5 D) 10 E) 20

How many cal is 542.0 kJ? A) 129.5

B) 542.0 C) 2267 D) 542,100 E) 129,500

Which of the following is the correct definition for the specific heat of a particular substance?

A) The amount of heat released when one gram of the substance is heated.

B) The temperature change when one gram of the substance is burned.

C) The amount of substance in grams which when cooled by 1°C releases 1kJ of

energy.

D) The amount of heat released when one gram of a substance is cooled by 1°C.

E) The amount of heat absorbed when the temperature increases by 1°C

A specimen weighing 100.0 g is heated from 30.00°C to 63.30°C. If the quantity of heat transferred is 5834 cal, determine the specific heat of the specimen.

A) 17.25 cal/ g·°C

B) 1.572 cal/ g·°C

C) 12.75 cal/ g·°C

D) 1.752 cal/ g·°C

E) 1.257 cal/ g·°C

What quantity of heat is transferred when a 250.0 g block of aluminum is heated from 25.00°C to 73.30°C? (Hint: The specific heat of aluminum = 0.2150 (cal/g·°C).)

A) 56160 cal

B) 2596 cal

C) 1.110 cal

D) 1298 cal

E) 8986 cal

Page 6

How much heat is necessary to melt 70 g of ice (solid H2O) at 0°C? The heat of fusion of H2O is 79.9 cal/g.

A) 73 cal

B) 79 cal

C) 5500 cal

D) 1400 cal

E) 5600 cal

What is the process by which a substance forms vapor directly from the solid state without becoming a liquid?
A) Melting
B) Sublimation

C) Fusion
D) Condensation E) Vaporization

Which of the following statements is true for the bonding of atoms?

A) The energy of a compound is equal to the energies of the atoms which make up the

compound.

B) The energy of the individual atoms is lower than the energy of the compound.

C) The formation of a compound naturally, from individual atoms requires external

energy.

D) When a compound disintegrates there is a release of energy which equals the

difference in energy between individual atoms.

E) Individual atoms have higher amounts of energy than when in a compound.

What term is used to describe the strength of interactions between atoms in an ionic compound?

A) Bond energy

B) Lattice energy

C) Chemical energy

D) Crystal energy

E) Ionic energy

The reaction between sodium metal and HCl gives off heat. This type of reaction is called an _____ reaction.

A) isothermal

B) exothermic

C) endothermic

D) energy requiring

E) energy-less

Page 7

Which of the following is an endothermic reaction?

A) 2H2 + O2  2H2O + 135 kcal

B) H2 + F2  2HF + 130 kcal

C) CH4 + 2O2  CO2 + 2H2O + 213 kcal

D) C2H4 + H2  C2H6 + 137 kJ

E) 2SnCl2 + 33 kcal  Sn + SnCl4

Which of the following is true about gases?

A) They have a definite shape.

B) Their particles are in close contact with each other.

C) They have no definite volume.

D) They take the shape of the bottom of the container.

E) They have strong intermolecular interactions.

As
other and with the walls of their container. The force generated by gas particles divided by the area of the container walls yields_____.
A) volume
B) pressure
C) temperature
D) amount
E) density

If a sample of gas has an initial pressure of 4.83 atm, what is the initial volume if the pressure is increased to 10.0 atm and the volume is reduced to 10.0 L? Assume that the amount and the temperature of the gas remain constant.

A) 10.0 L

B) 20.7 L

C) 4.83 L

D) 483L

E) 0.207 L

A sample of gas has Pi = 0.50 atm, Vi = 9.5 L, and Ti = 290 K. What is the final volume

if Pf A) B) C) D) E)

= 0.75 atm and Tf = 350 K? 7.6 mL
7.6 cL
7,600 cL

7,600 mL 7,600 L

HERE IS HOW THIS IS GOING TO WORK! IF YOU ANSWER THE QUESTIONS IWILL GIVE YOU THE 3K POINTS + MORE AFTER I REPOST IT.

2. The amount of heat involved in the synthesis of 1 mole of acompound from its elements, with all substances in their standardstates at 25*C, is called _________.

3. What is a valid unit for specific heat?

4. Use Hess's Law to find the heat of reaction in the examplebelow.

N2O4 (g) ----> 2NO2 (g)

Given that:

N2O4 (g) ----> N2 (g) + 2O2 (g) (Delta H =-9.7kJ)

2NO2 (g) ----> 2O2(g) + N2(g) ( Delta H= -67.7kJ)

5. Use Hess's Law to find the heat of reaction in the examplebelow. (Example doesn't exist btw.)

6. (Delta H) for the formation of rust (Fe2O3) is -826 kJ/mol. Howmuch energy is involved in the formation of 5 grams ofrust?

7. How many kilocalories of heat are required to raise thetemperature of 50g of aluminum from -5*C to 35*C? (Specific heat ofAluminum = 0.21 cal/g*C)

8.Calculate the (Delta H) for this reaction:

Zn(s) + Cu (2+ ion)(aq) ---> Zn(2+) + Cu(s)

(Delta H) for Cu(2+) = +64.4 kJ/Mol; (Delta H) for Zn(2+) = -152.4kJ/mol

9. The following equation shows the reaction that occurs whennitroglycerine explodes.

4C3H5O9N3 ----> 12CO2 + 6N2 + O2 +10H2O + 1725 Kcal

Is this reaction exothermic , endothermic, a combustion reaction ,or a combination reaction?

10. What does it mean for ammonia, (NH3) to have a (Delta H f) =-46 kJ/mol?

(for example: Define heat of formation. What does a negative heatof formation mean? what do the units of kJ/mol mean?)

11. What is the maximum amount of KCl that can dissolve in 500g ofwater?

(solubility of KCl is 34 g/ 100g of water at 20*C)

12.List the ways(operations) that can help make a substancedissolve faster in a solvent?

13. If a crystal added to an aqueous solution causes many particlesto come out of solution, the original solution was (saturate,unsaturated, supersaturated).

14. What is the number of moles of solute in 165 mL of a 0.82 Msolution?

15. What mass of NaCl is needed to make 350 mL of a 1.00 Msolution?

16. Colligative properties depend upon...

17. If one mole of each of these solutes in added to the sameamount of water, which solution has the highest boiling point?(glucose, aluminum sulfate, magnesium acetate, copper (I)chloride)

18. When an acid reacts with a base, what compounds areformed?

19. If the [H+] in a solution is 1x10^(-13) mol/L, what is the[OH-]?

20. If the [OH-] = 1x10^-6 mol/L, what is the pH of thesolution?

21. For a solution to be considered acidic what must be thehydrogen-ion concentration?

22. Which of the following represents a Bronsted-Lowry conjugateacid-base pair?

a) SO3(2-) and SO2 b) CO3(2-) and CO c) H3O and H2 d) NH4(+) and NH3

23. With solutions of "strong" acids and "strong" bases, the word"strong" refers to ...

24. What are the products of Al(OH)3 + H2CO3?

25.What is the concentration of hydrochloric acid if 5.0 mL of acidis neutralized by 30.0 mL of 2.00M sodium hydroxide.

26. At equilibrium, what is the rate of production of reactantscompared with the rate of production of products?

27. What is the equilibrium constant for the following reaction2SO3 ---> 2SO2 + O2

28. How does an increase in pressure affect the following reaction?2SO3 (g) --> 2SO2(g) +O2(g)

29.What stresses would shift the reaction to the right?

2SO3(g) ==> 2SO2(g) + O2(g)

30. The Keq of a reaction 4.9 x 10^(-7). Are products or reactantsfavored at equilibrium?

31. In which of these systems is the entropy decreasing?

a) air escaping from a tire b) snow melting c) a gas condensing d) salt dissolving inwater

32. If an atom is reduced in a redox reaction, what must occur toanother atom in the system?

33. Identify the oxidizing agent in the following reaction: 2Na + S---> Na2S

34. What are transferred in an oxidation -reductionreaction?

35. Give the oxidation number for each atom in KMnO4.

36. Which atom has a change in oxidation number of +4 in thefollowing reaction?

K2Cr2O7 + H2O + S ----> KOH + Cr2O3 +SO2

37. What is the oxidation number of sulfur in each of the following:

a. SO3 c.SO2(2-)

b. Na2SO4 d. S2O4 (2-)

38.Fe(3+) ----> Fe represents oxidation, reduction, orhydrolysis?

39. When the half reactions Br2+ 2e- -----> 2Br- and Na---->e- + Na(+) are combined the balanced redox equation is_____________________ ( WRITE the BALANCED REDOX eq)

40. To balance the oxygen and hydrogen for a redox reaction thattakes place in basic solution, it is necessary to use whichsubstance?

41. What particle completes this nuclear equation? 55/25 Mn + 2/1 H====> _____ +2 1/0 n

42. The half-life of tungsten-182 (182/74 W) is 1.1x10^(17) years.How long would it take for a 376.2 kg sample to decay until only123.0 grams remain?

43. After 3 days, the quantity of certain radioisotope is reducedfrom 13.6 grams to 1.9 grams. Calculate the half-life of theisotope.

44. What is the name of the compound having the formulaC8H18.

45. What is the name of the following compound:

O

//

CH3---CH2----CH---CH2--C

I \

CH3 OH

46. What is an isomer? Give an isomer of hexane (C6H14) and drawit's structure.

47. What is the name of the hydrocarbons with double covalentbonds?

48. Draw the stucture for 3-methylbutanoic acid.

49. Draw the structure for methylbenzene?

50. What is the name of the following compound:

Br

|

CH3----C-----CH3

|

CH3