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20 Nov 2019

In the following reactionCH4+CH4 arrow CH3CH3+H2two C-H bonds are broken(bond energy =412 kj/mol) to form a new C-C bond(bond energy=348 kj/mol and a new H-H bond(bond energy=436 kj/mol). Estimate the enthalpy in this reaction. Is it endothermic or exothermic:Hint for exothermic reactions the combined energies of the new bonds should be larger than the combined energies of the broken bonds.Balanced the following unbalanced reaction and calculate its standard free energy change(under standard reactions). State whether the reaction is spontaneous or nonspontaneous under standard conditionsC2H5OH(l)+O2(g) arrow CO2(g)+H2O(l) C2H5OH(l) O2(g) CO2(g) H2O(l) deltaH kj/mol -277.7 0 -393.5 -285.8 deltaG kjmol -174.8 0 -394.4 -237.1

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Elin Hessel
Elin HesselLv2
25 Apr 2019

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Related questions

I do not understand any of this, please help.

DearChegg Lifesaver. Here are the requirements:

1.Use given values as stated in questions below.

2.Clearly State Answer

3.(Please) LEAVE A COMMENT if you are currently working on anyproblems.

4.Formany of these problems you will need to use tabulated thermodynamicdata. Use the Information provided after problem 17.



---------------------------------------Questions---------------------------------------------------



1.Write a balanced formation equation for HNO3 at standardconditions. For the answer, enter the sum all of the coefficientsin the balanced equation. (If thisis not an integer, enter it as a decimal, not a fraction.)


2.Calculate ?H° for the following reaction:

SiO2(s)+ 4HF(g) ? SiF4(g) + 2H2O(g)


3.Use heat of formation data to determine ?H° for the reaction:

2NH3(g)? N2(g) + 3H2(g)


4.Calculate the mass of methane that must be burned to provide enoughheat to convert 330.0 g of water at 37.0°C into steam at 124.0°C.(Assume that the H2Oproduced in the combustion reaction is steam rather than liquidwater.)


5.Acetylene burns in air according to the following equation:

C2H2(g)+ 5/2 O2(g) ? 2 CO2(g) + H2O(g)

with?H° = -1255.8 kJ.

Giventhat ?Hf° for CO2(g) = -393.5 kJ/mol and ?Hf° for H2O(g) is -241.8kJ/mol, what is ?Hf° for C2H2(g)?






6.Given the following data:

HNO3(l)? 1/2N2(g) + 3/2O2(g) + 1/2H2(g) ?H° = 174.1 kJ

2N2O5(g)? 2N2(g) + 5O2(g) ?H° = -28.4 kJ

H2O(l)? H2(g) + 1/2O2(g) ?H° = 285.8 kJ


Calculate?H° for the reaction:

2HNO3(l)? N2O5(g) + H2O(l)

Notethat you should be able to answer this one without needing to useany additional information from the thermo table.


7.Hydrocarbons containing halogens are very useful molecules insynthetic chemistry. Use tabulated thermodynamic data as needed tocalculate ?Hf° for the reactionproduct in the equation shown below if ?H° for the reaction is-177.66 kJ.

C2H4(g)+ Cl2(g) ? CH2ClCH2Cl(g)



8.Identify the following statements as true or false. (Use thedrop-down menu and select "True" or "False" for each. You must getall 6 correct.)

Allsystems become more disordered spontaneously.

Both?Ssys and ?Ssurr must equal zero at equilibrium.

Theentropy of the universe is constant; the energy of the universedecreases towards a minimum.

Allspontaneous processes release heat.

Ifa reaction is spontaneous, the reverse reaction is non-spontaneous.

Ifa process decreases the randomness of the particles of a system,the entropy of the system increases.


9.Use tabulated thermodynamic data to calculate ?S° for the reaction:

PbO2(s)+ 2Ni(s) ? Pb(s) + 2NiO(s)



10.Calculate ?S° for the combustion of ethane (C2H6) to form carbondioxide and gaseous water.



11.Urea ((NH2)2CO) can be formed from ammonia and carbon dioxide asshown in the following reaction. The ?H° value for this synthesisis -134.0 kJ. Calculatethe ?H°f for urea.

2NH3(g)+ CO2(g) ? (NH2)2CO(s) + H2O(l)


12.The ?S° value for urea the synthesis reaction above is -424.0 J/K.Calculate S° for urea.

Tries0/99


13.Calculate ?G° for the synthesis of urea under standard conditions(298 K and 1 atm).

Tries0/99


14.Compute the standard free energy change for the following reaction.

O3(g)+ NO(g) ? NO2(g) + O2(g)

Tries0/99


15.The most important commercial process for generating hydrogen gasis the water-gas shift reaction:

CH4(g)+ H2O(g) ? CO(g) + 3H2(g)

Usetabulated thermodynamic data to find ?G° for this reaction at thestandard temperature of 25°C.


16.Now calculate ?G°1100 for this process when it occurs at 1100 K.


17.The molar enthalpy of fusion (?H°) of fluorine is 0.260 kJ/mol, andthe molar entropy of fusion (?S°) of fluorine is 4.851 J/mol K.Using this information,estimate the freezing point of fluorine. (You must answer inKelvin.)

substance

Δ

Hf

°

(kJ/mol)

Δ

Gf

°

(kJ/mol)		 S

°

(J/mol∙K)
Aluminum
Al3+ (aq) --- -485.0 ---
Al (s) 0 0 28.3
Al2O3 (s) -1675.7 -1582.3 50.9
Al(OH)3 (s) --- -1147.25 ---
Bromine
Br− (aq) --- -104.0 ---
Br2 (l) 0 0 152.2
Br2 (g) 30.9 3.1 245.5
HBr (g) -36.3 -53.4 198.7
Calcium
Ca2+ (aq) --- -553.6 ---
CaCl2 (s) -795.4 --- ---
CaO (s) -634.9 --- ---
Ca(OH)2 (s) -985.2 --- ---
Ca3(PO4)2 (s) --- -3884.7 ---
Carbon
C (s) 0 0 5.7
CCl4 (g) -95.7 -64.0 309.4
CCl4 (l) -128.2 -68.6 214.4
CCl4 (s) -136.8 --- ---
CH4 (g) -74.6 -50.5 186.3
C2H2 (g) 227.4 --- ---
C2H6 (g) -84.0 --- ---
C3H8 (g) -103.85 -23.4 270.3
C4H10 (g) -125.7 -15.7 310.0
C4H10 (l) -147.3 -15.0 231.0
C6H6 (l) 49.1 124.5 173.4
C6H6 (g) 82.9 129.7 269.2
CH3OH (l) -239.2 -166.6 126.80
CH3OH (g) -201.0 -162.3 239.9
(CH3)2(CH2)2O (l) -279.5 -346.74 253.5
C6H12O6 (s) -1237.3 -910.4 212.1
CO (g) -110.5 -137.2 197.7
CO2 (g) -393.5 -394.4 213.8
C2H5OH (l) -277.6 -174.8 160.7
C2H5OH (g) -234.8 -167.9 281.6
HCH3CO2 (l) -484.3 -389.9 159.8
HCH3CO2 (s) -472.8 --- ---
HCH3CO2 (g) -432.2 --- 283.5
HCN (l) 108.9 125.0 112.8
HCN (g) 135.1 124.7 201.8
CS2 (s) 93.8 --- ---
CS2 (l) 89.0 64.6 151.3
CS2 (g) 116.7 67.1 237.8
Chlorine
Cl2 (g) 0 0 223.1
Cl− (aq) --- -131.2 ---
HCl (aq) -167. --- ---
HCl (g) -92.3 -95.3 186.9
Chromium
CrO42− (aq) --- -727.8 ---
Fluorine
F2 (g) 0 0 202.8
HF (g) -273.3 -275.4 173.8
Hydrogen
H2 (g) 0 0 130.7
Iron
Fe (s) 0 0 27.3
FeCl3 (s) -399.5 -334.0 142.3
Fe2O3 (s) -824.2 -742.2 87.4
Lead
Pb2+ (aq) --- -24.4 ---
PbBr2 (s) -278.7 -261.9 161.5
PbS (s) -100.4 -98.7 91.2
PbSO4 (s) -920.0 -813.0 148.5
Magnesium
MgCl2 (s) -641.3 -591.8 89.6
MgO (s) -601.6 -569.3 27.0
Mercury
Hg (g) 61.4 31.8 175.0
Hg (l) 0 0 75.9
Hg (s) -2.29 --- ---
Hg22+ (aq) --- 153.5 ---
Hg2Cl2 (s) --- -210.7 ---
Nitrogen
N2 (g) 0 0 191.6
N2H4 (g) 95.4 159.4 238.5
N2H4 (l) 50.6 149.3 121.2
NH3 (g) -45.9 -16.4 192.8
NH3 (l) -69.54 -26.50 95.09
NH4NO3 (s) -365.6 -183.9 151.1
NO (g) 91.3 87.6 210.8
NO2 (g) 33.2 51.3 240.1
NOCl (g) 51.7 66.1 261.7
N2O4 (g) 11.1 99.8 304.4
HNO2 (g) -79.5 --- ---
HNO3 (l) -174.1 -80.7 155.6
HNO3 (g) -133.9 -73.5 266.9
Oxygen
OH− (aq) --- -157.2 ---
H2O (l) -285.8 -237.1 70.0
H2O (g) -241.8 -228.6 188.8
O2 (g) 0 0 205.2
H2O2 (l) -187.8 -120.4 109.6
H2O2 (g) -136.3 -105.6 232.7
Phosphorus
P4 (s) 0 0 41.
P4 (g) 58.9 24.4 280.0
PCl3 (g) -287.0 -267.8 311.8
PCl3 (l) -319.7 -272.3 217.1
PF5 (g) -1594.4 -1520.7 300.8
PO43− (aq) --- -1018.7 ---
H3PO4 (l) -1271.7 --- ---
H3PO4 (s) -1284.4 -1124.3 110.5
P4O10 (s) -2984. -2675.2 228.9
Potassium
KBr (s) -393.4 -380.7 95.9
KNO3 (s) -492.7 -393.13 132.9
Silver
Ag+ (aq) --- 77.1 ---
Ag2CrO4 (s) --- -641.8 ---
Sodium
NaCl (s) -411.2 --- ---
NaOH (s) -425.8 --- ---
Sulfur
S8 (s) 0 0 32.0
H2S (g) -20.6 --- ---
H2SO4 (l) -814.0 --- ---
SF6 (g) -1220.5 -1116.5 291.5
Tin
Sn (s) 0 0 51.2
SnO2 (s) -577.6 -515.8 49.0
Titanium
TiCl4 (g) -763.2 -726.3 353.2
TiCl4 (l) -804.2 -737.2 252.3
TiO2 (s) -944.0 -888.8 50.6

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