# The standard molar enthalpy of fusion and the standard molar enthalpy of vaporization of benzene are 10.9 kJ/mol and 31.0 kJ/mol, respectively. Calculate the standard molar entropy changes for the solid ↔ liquid and liquid ↔ vapor transitions for benzene.

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1. ### Chem (Thermodynamics)

The standard molar enthalpy of fusion and the standard molar enthalpy of vaporization of benzene are 10.9 kJ/mol and 31.0 kJ/mol, respectively. Calculate the standard molar entropy changes for the solid ↔ liquid and liquid ↔ vapor transitions for benzene. At 1 atm ...
2. ### chemistry

A method for scrubbing CO2(g) from the air on a spacecraft is to allow CO2(g) to react with NaOH according to the following (unbalanced reaction). NaOH(s) + CO2(g) → Na2CO3(s) + H2O(l) Use the appropriate thermodynamic tables to calculate the enthalpy, entropy and ...
3. ### Chemistry

Calculate the heat (in kJ) required to transform 58.60 g of dinitrogen tetraoxide from a solid at a temperature of -9.3 °C to a gas at 47 °C. Report your answer to one decimal place. Data: Molar mass of dinitrogen tetraoxide, N2O4 = 92.011 g/mol Melting point = -9.3 °C ...
4. ### chemistry

2.9 The standard enthalpy of formation of the metallocene bis(benzene)chromium was measured in a calorimeter. It was found for the reaction Cr(C6H6)2(s) → Cr(s) + 2 C6H6(g) that . Find the corresponding reaction enthalpy and estimate the standard enthalpy of formation of...
5. ### Chemistry

"Translate the empirical molar enthalpy given below into a balanced chemical equation, including the enthalpy change (delta H): The standard molar enthalpy of formation for carbon disulfide is 89.0 kJ/mol" I got delta H = 178 kJ (is that right?). However, I'm having trouble ...
6. ### CHEMISTRY

Calculate the change in entropy that occurs when 17.68 g of ice at -12.7°C is placed in 54.05 g of water at 100.0°C in a perfectly insulated vessel. Assume that the molar heat capacities for H2O(s) and H2O(l) are 37.5 J K-1 mol-1 and 75.3 J K-1 mol-1, respectively, and the ...
7. ### Chem

the standard molar enthalpy and entropy of the denaturation of a certain protein are 512 kj/mol and 1.60 kj/K. mol, respectively . comment on the sign s and magnitudes of these quantities, and calculate the temperature at which the process favors the denatured state
8. ### chemisty

The molar heat capacity of C6H6(ℓ) is 136 J/mol ·◦C and of C6H6(g) is 81.6 J/mol · ◦C. The molar heat of fusion for benzene is 9.92 kJ/mol and its molar heat of vaporization is 30.8 kJ/mol. The melting point of benzene is 5.5 ◦C, its boiling point is ...
9. ### Chem 2 enthalpy

How much heat is evolved when 25.5 g of benzene freezes at 5.5 Celcius (molar heat of fusion is 9.94 kJ/mol and molar mass of benzene= 78.0 g/mol)
10. ### chemistry

The molar enthalpy of vaporization for water is 40.79 kJ/mol. Express this enthalpy of vaporization in joules per gram. b. The molar enthalpy of fusion for water is 6.009 kJ/mol. Express this enthalpy of fusion in joules per gram.
11. ### chemistry, please help

2NO2(g)--> 2NO(g) + O2(g) , H=+114.2kJ (Note: H, S, G all have a degree sign next to them) NO: H(enthalpy)=90.3kJ/mol, S(entropy)=210.7J/mol*K, G(gibbs energy)=86.6 O2: H(enthalpy)=0, S(entropy)=?, G(gibbs energy)=0 kJ/mol NO2: H(enthalpy)=33.2, S=239.9, G=51 For part a, I ...
12. ### Chemistry

How much heat is released when 75.0 g of steam at 100.0°C is cooled to ice at -15.0°C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol °C), and the molar heat ...
13. ### Gen Chem

If the standard enthalpy of combustion of octane, C8H18(l) is -5471 kJ/mol, calculate the enthalpy change when 1.00 kg of octane are burned. the molar mass of octane is 114 g/mol
14. ### Chemistry

If the standard enthalpy of combustion of octane, C8H18(l) is -5471 kJ/mol, calculate the enthalpy change when 1.00 kg of octane are burned. the molar mass of octane is 114 g/mol
15. ### Chemistry

Calculate the entropy change in the surroundings when 1.00 mol N2O4(g) is formed from 2.00 mol NO2(g) under standard conditions at 298 K. I get +192 J/K. The book says -192 J/K. Here is my work, where am I going wrong? Standard Enthalpy of NO2(g) = 33.18 kJ/mol * 2 mol = 66.36...
16. ### Chemistry

When 0.3212g of glucose was burned in bomb calorimeter of calorimeter constant 641J/K, the temperature rose by 7.943 K. Calculate a) the standard molar internal energy of combustion b) the standard enthalpy of combustion and c) the standard enthalpy of formation of glucose. (...
17. ### Chemistry

The known molar volume of gases is 22.4 L at standard condition. Calculate the molar volume under standard conditions from your data. I am not sure what the instruction asks. By molar volume, does it mean convert moles to volume. Like this: (.004 mol O2)(22.4 L O2/1 mol O2) =....
18. ### Chemistry

A sample of acetone having a mass of 1.920 g undergoes complete combustion in an insulated calorimeter holding 400 mL of water. It is determined that the water and calorimeter together absorb 58.829 kJ of heat energy from this combustion. Based on this information, what is the...
19. ### chemsitry

c. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard enthalpy of formation of gaseous carbon dioxide is -393.5 kJ/mol The ...
20. ### gen Chem

I've attempted this problem but not sure if i'm on the right track. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard ...
21. ### Chemistry

Consider the isomerization equlibria of an alkene (C4H8) that co-exists as three isomers. (These 3 are in an equlibrium triangle) Reaction 1: cis-2-butene ⇔ trans-2-butene Reaction 2: cis-2-butene ⇔ 2-methylpropene Reaction 3: trans-2-butene ⇔ 2-methylpropene...
22. ### CHEMISTRY HELP

1) The specific heat of solid copper is 0.385 J/g(C). What thermal energy change occurs when the temperature of a 34.10 g sample of copper is cooled from 35.7 degrees Celsius to 13.9 degrees Celsius? Answer: -286.3 J This amount of heat is used to melt solid ice at 0.0 degrees...
23. ### Chem

I'm unbelievably stuck on this problem. Any help would be appreciated. Red phosphorous is formed by heating white phosphorous. Calculate the temperature at which the two forms are at equilibrium, given white P: (heat of formation)= 0.00 kj/mol; standard molar entropy= 41.09 J/...
24. ### general chemistry

A sample consisting of 0.025 mol of a solid compound is placed inside a metal cylinder. The cylinder was immersed in a water bath consisting of 10.00 kg of water at an original temperature of 25.00 °C. When the compound decomposes, the temperature of the water rises to 29.52...
25. ### college chem

Calculate the molar enthalpy of reaction standard enthalpy of formation below. H20 = -285.8 kj/mole H+ = 0.0 kj/mole OH- = -229.9 kj/mol H+(aq) + OH-(aq)→H2O(l) For this, don't you do the summation of products x stoichemtry + the sum of reactants x stoich. from there I'm...
26. ### chemistry

use the following data to calculate the mean bond enthalpy values for the C-H and C-C bonds. CH4(g)-C(g) + 4H(g) standard enthalpy change is +1648 kj/mol C2H6(g)-2C(g) + 6H(g) standard enthalpy change is +2820 kj/mol
27. ### Chemistry

The molar enthalpy of vaporization for water is 40.79 kJ/mol. Express this enthalpy of vaporization in joules per gram.
28. ### Chemistry

If calcium carbide has a standard enthalpy of formation of -59.8 kJ/mol and acetylene has a standard enthalpy of formation of 226.73 kJ/mol, what is the standard enthalpy change for the reaction?
29. ### Chemistry

1.What is the molar heat of vaporization of water, given the following thermochemical equations? H2 + 1/2 O2 --> H2O + 241.8 kJ H2 + 1/2 O2 --> H2O + 285.5 kJ a) 44.0 kJ/mol b)-44.0 kJ/mol c)241.8 kJ/mol 2. Which substance has a standard enthalpy of formation delta Hf, ...
30. ### college chemistry

at its melting point, O c, the enthalpy of fusion of water is 1.435 kcal/mol. what is the molar entropy change for the melting ice at 0C? answer: 5.26 cal/mol-k
31. ### Chemistry

Calculate the entropy change when 2.42 g of H2 reacts with O2 according to the reaction 2 H2(g) + O2(g) → 2 H2O(ℓ) at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ) at 298 K is −285.8 kJ/mol. The corresponding free energy ...
32. ### Chemistry

Calculate the entropy change when 2.42 g of H2 reacts with O2 according to the reaction 2 H2(g) + O2(g) → 2 H2O(ℓ) at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ) at 298 K is −285.8 kJ/mol. The corresponding free energy ...
33. ### Chemistry

Lithium metal is a highly reactive metal that oxidizes instantly in water or air. Given the data below, calculate the energy required to heat 10.0 g of Li from 150.0 °C to 200.0 °C. Molar heat capacity (solid) = 3.58 J/°C • mol Molar heat capacity (liquid) = 4.379 J/°C...
34. ### Chemistry

Rewrite the following using a thermochemical equation with a deltaH value: a) The standard molar enthalpy of combustion for propane is -2220kJ/ mol.
35. ### Chemistry

CCl3F boils at 23.8 degrees Celcius, and its molar heat of vaporization is 24.8 kJ/mol. Calculate the molar entropy of vaporization of CCl3F (l)
36. ### Chemistry - Science (Dr. Bob222)

Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g)  N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were produced in the gaseous rather than the liquid ...
37. ### chemistry

The standard molar entropy value of N2 (g) is 191.5 J/K-mol, of O2 (g) is 205.0 J/K-mol and of NO2 (g) is 240.0 J/K-mol. From these values we can calculate the Delta S for the reaction N2 (g) + 2 O2 (g) produces 2 NO2 (g) to be a. – 156.5 J/K b. 636.5 J/K c. 15.5 J/K d. – ...
38. ### General Chemistry 2

The molar heat of vaporization of benzene is 31kj/mol. Calculate the entropy change for the liquid vapor equilibrium. At 1 atm pressure, benzene boils at 80.1 degrees Celsius.
39. ### AP Chemistry

Calculate the entropy change when 4.88 g of H2 reacts with O2 according to the reaction 2H2(g) + O2(g)→2H2O(ℓ)at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(ℓ)at 298 K is −285.8 kJ/mol. The corresponding free energy of ...
40. ### Chemistry

Consider the process where 1.3 moles of ice, initially at -30.0 C, is heated to 140.0 C at constant pressure of 1.00 atm. The molar heat capacities (Cp) for solid, liquid, and gaseous water (37.5 J K-1 mol-1, 75.3 J K-1 mol-1, 36.4 J K-1 mol-1, respectively) are assumed to be ...
41. ### Chemistry

Consider the process where 1.3 moles of ice, initially at -30.0 C, is heated to 140.0 C at constant pressure of 1.00 atm. The molar heat capacities (Cp) for solid, liquid, and gaseous water (37.5 J K-1 mol-1, 75.3 J K-1 mol-1, 36.4 J K-1 mol-1, respectively) are assumed to be ...
42. ### Science

Is the molar enthalpy of combustion of pentane the same as the molar enthalpy of formation of pentane? No. The molar enthalpy for the combustion is for the reacton C5H10 + (15/2)O2 ==> 5CO2 + 5H2O The molar enthalpy for the formaton is 5C(graphite) + 5H2(g) ==> C5H10(l) ...
43. ### Chemistry

The standard entropy change for 1.00 moles of Ar as it evaporates at -185.7 °C (∆H°-185.7 = 1558 cal mol-1) is? 1. 17.8 J mol-1K-1 2. 87.5 J mol-1K-1 3. 15.0 J mol-1K-1 4. 46.0 J mol-1K-1 5. 74.5 J mol-1K-1 6. none of the previous answers I thought I would use deltaG=...
44. ### Chemistry

The standard change in internal energy for the combustion of buckyball is -25,968 kJ/mol. What is the enthalpy of combustion? What is the enthalpy of formation of buckyball? What is the molar enthalpy associated with converting buckyball to graphite? How does this compare to ...
45. ### Chemistry

The standard molar heat of fusion of ice is 6020 J/mol. Calculate q, w, and (delta) E for melting 1.00 mol of ice at 0 deg. C and 1.00 atm pressure.
46. ### chemistry

The standard molar heat of fusion of ice is 6020 J/mol. Calculate q, w, and ∆E for melting 1.00 mol of ice at 0◦C and 1.00 atm pressure.
47. ### chemistry

3.5 moles of steam at 100 C are condensed at 100 C and the resulting water is cooled to 42.3 C. Calculate the entropy change for this process.(The molar heat capacity of liquid water is 75.3 J mol1 K1, and the molar enthalpy of vaporisation of water is 40.8 kJ mol/1 at 100 C).
48. ### college chemistry

the normal freezing point of the element mercury, Hg(l), is a -38.9°C and its molar enthalpy of fusion, ΔHfusion=2.29 KJ/mol. What is the entropy change (J/K) of the system when 50 g of Hg(l) freezes at the normal freezing point. Hg= 200.59 g/mol
49. ### Chemistry

This isn't exactly a homework question, I'm just trying to understand the concept we learned today... So say we had: 4Fe + 3O2 → 2Fe2O3 + 1.65 x 10^3 kJ Does that mean for every 4 mol of Fe, 3 mol of O2, and 2 mol of Fe2O3 we have 1.65 x 10^3 kJ? And if I were to ...
50. ### Chemistry

Calculate the entropy change accompanying conversion of 1 mole of ice at 273 K and 1 atm pressure into steam at 373 K and 1 atm pressure, given that at 273 K, the molar heat of fusion of ice is 6 kJ/mol and at 373 K, the molar heat of vapourization of water is 40.60 kJ/mol. ...
51. ### chemistry

The standard enthalpy of combustion of C2H6O(l) is -1,367 kJ mol-1 at 298 K. What is the standard enthalpy of formation of C2H6O(l) at 298 K? Give your answer in kJ mol-1, rounded to the nearest kilojoule. Do not include units as part of your answer. Note: The standard ...
52. ### Chemistry

The following reaction has a standard enthalpy of reaction of -146.0 kJ/mol: Cu2O(s) + 1/2 O2(g) -> 2CuO(s) The standard enthalpy of formation of Cu2O(s) is -168.6 kJ/mol. What is the standard enthalpy of formation of CuO(s)?
53. ### chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Substance So (J/mol∙K) ∆Hºf (kJ/mol) C2H2(g 200.9 226.7 H2(g) 130.7 0 C2H6(g) -- -84.7 Bond Bond Energy (kJ/mol) C-C 347 C=C 611 C-H 414 H-H 436 If the value of the standard entropy change, ∆Sº for the reaction is -232.7 ...
54. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Substance So (J/mol∙K) ∆Hºf (kJ/mol) C2H2(g 200.9 226.7 H2(g) 130.7 0 C2H6(g) -- -84.7 Bond Bond Energy (kJ/mol) C-C 347 C=C 611 C-H 414 H-H 436 If the value of the standard entropy change, ∆Sº for the reaction is -232.7 ...
55. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Substance So (J/mol∙K) ∆Hºf (kJ/mol) C2H2(g 200.9 226.7 H2(g) 130.7 0 C2H6(g) -- -84.7 Bond Bond Energy (kJ/mol) C-C 347 C=C 611 C-H 414 H-H 436 If the value of the standard entropy change, ∆Sº for the reaction is -232.7 ...
56. ### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -172.4 kJ : 2SO2(g) + O2(g) 2SO3(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of SO2(g) is what in kJ/mol?
57. ### chemistry - Molar enthalpy

When 10.0 g of KOH is added to 100.0 g water, the solution's temperature increases from (25.18 C) to (47.53 C). What is the molar enthalpy of solution for KOH? i tryed q=(m)x(c)x(delta T) didn't really work. i got 22.35 J do i use that to find the molar enthalpy if so how?
58. ### Chemistry - Energy Phase Changes

Calculate the quantity of heat gained or lost in the following change: 0.44 mol of water evaporates at 100 degrees Celsius - So what I did was: 1 mol -> 6.01 kJ 0.44 mol -> x x = 2.64 kJ of energy gained But apparently this is incorrect? Could somebody please explain to ...
59. ### chem

The bond enthalpy of N2(g) is 418.0 kJ/mol. Calculate ÄH°f for N(g). I figured that if it gave the enthalpy for N2, then the enthalpy for N would be half of the given amount. But that wouldn't be bonded to anything?? Is there a standard calculation?
60. ### Chemistrey

Lab exercise 10C Calibrating bomb Calorimeter Before Molar specific enthalpies of reaction can be determined, a bomb calorimeter must be calibrated using primary standard of precisely known molar enthalpy. Complete the analysis of the investigation report. Problem: What is the...
61. ### Chem

For the reaction, 3C2H2(g) ===> C6H6 at 25°C, the standard enthalpy change is -631 kJ and the standard entropy change is -430 J/K, Calculate the standard free energy change (in kJ) at 25°C. What is the formula that relates stand. entropy, enthalpy and free energy changes?
62. ### Chemistry

The normal boiling point of bromine (Br2) is 58.8°C, and its molar enthalpy of vaporization is ΔHvap = 29.6 kJ/mol. Calculate the value of ΔS when 1.00 mol of Br2(l) is vaporized at 58.8°C.?
63. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Information about the substances involved in the reaction represented above is summarized in the following tables. Substance/ So (J/mol∙K) /∆Hºf (kJ/mol) C2H2(g) / 200.9 / 226.7 H2(g) / 130.7 / 0 C2H6(g)/ ?? / -84.7 Bond Bond Energy...
64. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Information about the substances involved in the reaction represented above is summarized in the following tables. Substance/ So (J/mol∙K) /∆Hºf (kJ/mol) C2H2(g) / 200.9 / 226.7 H2(g)/ 130.7 / 0 C2H6(g)/ ?? / -84.7 Bond Bond Energy...
65. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Information about the substances involved in the reaction represented above is summarized in the following tables. Substance So (J/mol∙K) ∆Hºf (kJ/mol) C2H2(g) 200.9 226.7 H2(g) 130.7 0 C2H6(g) - - -84.7 Bond Bond Energy (kJ/mol) C-...
66. ### Chemistry

C2H2(g) + 2 H2(g)--> C2H6(g) Information about the substances involved in the reaction represented above is summarized in the following tables. Substance/ So (J/mol∙K) /∆Hºf (kJ/mol) C2H2(g) / 200.9 / 226.7 H2(g) / 130.7 / 0 C2H6(g)/ ?? / -84.7 Bond Bond Energy...
67. ### Chemistry

Calculate the standard entropy, ΔS°rxn, of the following reaction at 25.0 °C using the data in this table. The standard enthalpy of the reaction, ΔH°rxn, is –44.2 kJ·mol–1. C2H4(G)+H20 ---> C5H5OH ΔS°rxn= ______ J*K^-1*mol^-1 Then, calculate the ...
68. ### chemistry

The molar heat of fusion of benzene is 9930 J/mol and ∆s= 35.7 j/mol-deg. Calculate the melting point.
69. ### Chemistry

C2H5O2N is an important compound. The combustion reaction of glycine proceeds according to this equation: 4C2H5O2N + 9O2 ---> 8Co2 +10H2O +2N2 which is = -3857 kJ Given CO2 is -393.5 kJ/mol Given H2O is -285.6 Calculate the standard molar enthalpy of formmation of glycine.
70. ### marian university college

The molar constant-pressure heat capacity of a certain solid at 4.2 K is 0.43 J K−1 mol−1. What is its molar entropy at that temperature?
71. ### chemistry!

The standard molar heat of vaporization for water is 40.79 kJ/mol. How much energy would be required to vaporize 4.00 mol of water? Answer in units of kJ
72. ### Enthalpy Chemistry

Can someone make sure I did this write! What is the molar change in enthalpy when 100 g of ice is heated from -18.2 C to -72 C (Cp = 37.4 J/K*mol) 100g of ice = 100 g/-18.2 C = 5.56 mol 5.56 mol * 37.4 J/K * mol * 53.8 K = 1118 J
73. ### Chemistry

68.0g of solute were dissolved in 393 mL of benzene. The solution froze at -0.50°C. The normal freezing point of benzene is 5.5°C and the molar freezing point constant is 5.12°C kg/mol. The density of benzene is .879 g/mol. Calculate the molar mass of the solute.
74. ### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) is kJ/mol
75. ### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) is kJ/mol
76. ### CHemistry....Please help

1.SOLUBILITY: At 25C, the molar solubility of calcium phosphate in water is 1.1*10^{-7}M. Calculate the solubility in grams per liter. I m not sure how to convert M to g/L MOLAR MASS OF COLLIGATIVE PROPERTIES: 2.tert-Butyl alcohol is a solvent with a Kf of 9.10 C/m and a ...
77. ### Chemistry

How do I find the molar enthalpy H (kJ/mol) for reaction of NH3 + HCl -> NH4Cl at temp 9.8 celsius by using Hess's Law. I do not understand why there are unknown variables and how to use that to find the molar enthalpy. PLEASE HELP. 1/2 N2 + 3/2 H2 + xH2o -> NH3 H= -80.7...
78. ### Chemistry help

I am not to sure how to approach the problem... Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g) ==> N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were ...
79. ### Chem

Change in enthalpy problem. Consider the reaction represented below. Referring to the data in the table below, calculate the standard enthalpy change for the reaction at 25 degrees C. O3(g)+NO(g)-->O2(g)+NO2(g) Standard enthalpy of formation in kJ/mol: O3(g) 143 NO(g) 90 ...
80. ### chemistry

Calculate the standard enthalpy change for the reaction OF2 (g) + H2O (l) → O2 (g) + 2HF (g). Standard enthalpies of OF2, H2O, and HF are 20 kJ mol-1, -285 kJ mol-1, and -270 kJ mol-1 respectively.
81. ### Chermistry

if molar enthalpy of vaporization of enthanol is 38.6 kJ/mol, how many moles of ethanol are vaporize when required heat is 200.72kJ
82. ### Chemistry 30

Calculate the molar heat of reaction for the NaOH(aq) using the data obtained from this experiment. (this is a neutralization question) H2so4 Volume= 30ml Concentration=1.0mol/l Initial temp. = 29.9 NAOH Volume= 50ml C = 1.0 mol/L Initial temp. = 29 Final temp of the two ...
83. ### Chemistry

Table sugar consists mostly of sucrose, C12H22O11. The standard enthalpy of combustion for sucrose is the standard state delta H for the reaction: C12H22O11 + 12 O 2 ---> 12 CO2 + 11 H2O Calculate this standard state delta H. Give answer in units of kJ to five significant ...
84. ### Chemistry

In one experiment, the mass of water is 92.6 grams, the initial temperature of the water is 67.6oC, the mass of liquid nitrogen added to the water is 61.4 grams, and the final temperature of the water, after the liquid nitrogen has vaporized, is 35.6oC. Specific heat of water...
85. ### Chemistry

If the standard enthalpy of formation of PH3(g) is +5.4 kJ mol-1, calculate the reaction enthalpy for 2PH3(g)--->2P(s)+3H2(g)
86. ### chemistry

3. Calculate the standard entropy change for the reaction: N2 + 3H2 → 2NH3 given the standard entropies Sº(N2)(g) = 191.6 J K^-1 mol^-1 Sº(H2)(g) = 130.6 J K^-1 mol^-1 Sº(NH3)(g) = 193.3 J K^-1 mol^-1
87. ### chemistry

How much does the molar enthalpy change when 147g of water cools from 90°C to 17.0°C? The molar heat capacity for water is 75.3 j/k•mol
88. ### chemistry

calculate the standard molar entropy change for the combustion of methane gas using S naught values from standard thermodynamic tables. Assume that liquid water is one of the products.
89. ### Chemistry

Use standard heats of formation in Appendix L to calculate standard enthalpy changes for the following reactions. 1.45 x 10-2 mol of carbon is oxidized to CO2(g) Please help me!
90. ### Chem

how would I calculate the molar enthalpy for NaOH in KJ/mol
91. ### Chemistry

What would you do in order to solve this question: "The enthalpy of combustion for benzoic acid is -3223.6kj/mol. Use the values of the standard enthalpies of formation of liquid water and CO2 to calculate standard enthalpy of formation of benzoic acid."
92. ### Chemistry 11

A hydrate of zinc chlorate, Zn(ClO3)2 .xH2O(s) contains 21.5% zinc by mass. Find the value of x. What I've done: Molar mass of Zn: 65.409 g/mol Molar mass of Cl: 2*35.453 =70.906 g/mol Molar mass of O: 6*15.9994 =95.9964 g/mol Total molar mass of Zn(ClO3)2: 232.3114 g/mol 21% ...
93. ### chemistry

a sample consisting 22.7g of a nongasous unstable compound X is placed inside a metal cylinder with a radius of 8Cm and a piston is carefully placed on the surface of the compound so that for all practical purposes the distance between the bottom of the cylinder and the piston...
94. ### chemistry

I have solved the following question but i am not sure whether it is right or wrong.. Calculate the molar heat of reaction for the NaOH(aq) using the data obtained from this experiment. (this is a neutralization question) H2so4 Volume= 30ml Concentration=1.0mol/l Initial temp...
95. ### Chemistry(Please check answers)

1) The standard molar entropy value of N2 (g) is 191.5 J/K-mol, of O2 (g) is 205.0 J/K-mol and of NO2 (g) is 240.0 J/K-mol. From these values we can calculate the Delta So for the reaction N2 (g) + 2 O2 (g)-> 2 NO2 (g) to be? I did products - reactants (240 X 2) - [191.5...
96. ### chemistry

Calculate enthalpy change of reaction for the combustion of gaseous ethanol. C2H5OH + 3O2 >> CO2 + 3H2O. Using standard molar enthalpies of formation. C2H5OH -235.3 ( it's negative sign) CO2 -393.5 H2O -241.8 (1) Calculate the enthalpy change of reaction per mole of ...
97. ### Chemistry

The enthalpy of vaporization of chloroform (CHCl3) is 29.2 kJ mol-1 at its normal boiling point 61.2 Celsius. what is the standard change in entropy for vaporization of chloroform at its normal boiling point? Answer I got was 29.2/334.2 = 0.0873. (CORRECT?)
98. ### chem

At standard pressure, ammonia melts at 195 K and boils at 240 K. If a sample of ammonia at standard pressure is cooled from 200 K down to absolute zero, what physical constants are needed to calculate the change in enhtalpy? I) the heat capacity of ammonia(s) II) the heat ...
99. ### chemistry

At standard pressure, ammonia melts at 195 K and boils at 240 K. If a sample of ammonia at standard pressure is cooled from 200 K down to absolute zero, what physical constants are needed to calculate the change in enhtalpy? I) the heat capacity of ammonia(s) II) the heat ...
100. ### Chemistry

Calculate the molar enthalpy of reaction per mole of carbon in the following reaction: 3 C(s) + 2 Fe2O3(s) + 466 kJ c12-u3_files/i0210000.jpg 4 Fe(s) + 3 CO2(g) a. +466 kJ/mol C b. +155 kJ/mol C c. +117 kJ/mol C d. –466 kJ/mol C e. –155 kJ/mol C