8. Thermochemistry
Enthalpy of Formation
8. Thermochemistry
Enthalpy of Formation - Video Tutorials & Practice Problems
Get help from an AI Tutor
Ask a question to get started.
The Enthalpy of Formation for an element is a key component in determining the enthalpy of reaction.
Enthalpy of Formation
1
concept
Enthalpy of Formation
Video duration:
2mPlay a video:
2
example
Enthalpy of Formation Example 1
Video duration:
3mPlay a video:
3
Problem
ProblemThe oxidation of ammonia is illustrated by the following equation:
Calculate the enthalpy of reaction, ΔHRxn, based on the given standard heats of formation.
A
-906 kJ
B
-1273.2 kJ
C
1089.6 kJ
D
-183.6 kJ
4
Problem
ProblemConsider the following equation:
2 ClF3(g) + 2 NH3(g) → 1 N2(g) + 6 HF (g) + 6 Cl2(g) ΔHrxn = –1196 kJ
Determine the standard enthalpy of formation for chlorine trifluoride, ClF3.
A
-175.1 kJ
B
350.2 kJ
C
442.0 kJ
D
-1638 kJ
Do you want more practice?
We have more practice problems on Enthalpy of Formation
Your General Chemistry tutor
Additional resources for Enthalpy of Formation
PRACTICE PROBLEMS AND ACTIVITIES (92)
- A table of standard enthalpies of formation (ΔH°f) gives a value of −467.9 kJ/mol for NaNO3(s). Which reaction...
- What is ΔH for the explosion of nitroglycerin? (LO 9.14) 2 C3H5(NO3)3(l) → 3 N2(g) + 1/2 O2(g) + 6 CO2(g) + 5 ...
- Atomic hydrogen (H) is used in welding (AHW). The atoms recombine to hydrogen molecules with a large release o...
- Consider the following equilibrium between oxides of nitrogen 3 NO1g2 Δ NO21g2 + N2O1g2 (a) Use data in Append...
- Methanol 1CH3OH2 can be made by the reaction of CO with H2: CO1g2 + 2 H21g2 Δ CH3OH1g2 (a) Use thermochemical ...
- Acetylene 1C2H21g22 is used for welding because oxyacetylene is the hottest burning common fuel gas. Using sta...
- The fuel in high-efficiency natural-gas vehicles consists primarily of methane 1CH42. (a) How much heat is pro...
- Using values from Appendix C, calculate the value of H for each of the following reactions: (a) CaO1s2 + 2HF...
- Zinc metal reacts with hydrochloric acid according to the balanced equation: Zn(s) + 2 HCl(aq)¡ZnCl2(aq) + H2(...
- Complete combustion of 1 mol of acetone 1C3H6O2 liberates 1790 kJ: C3H6O1l2 + 4 O21g2 ¡ 3 CO21g2 + 3 H2O1l2 H°...
- Calcium carbide 1CaC22 reacts with water to form acetylene 1C2H22 and Ca1OH22. From the following enthalpy of ...
- Gasoline is composed primarily of hydrocarbons, including many with eight carbon atoms, called octanes. One o...
- Ethanol 1C2H5OH2 is blended with gasoline as an automobile fuel. (d) Calculate the mass of CO2 produced per...
- Ethanol 1C2H5OH2 is blended with gasoline as an automobile fuel. (c) Calculate the heat produced per liter of...
- Methanol 1CH3OH2 is used as a fuel in race cars. (b) Calculate the standard enthalpy change for the reaction,...
- Hydrazine (N2H4) is a fuel used by some spacecraft. It is normally oxidized by N2O4 according to the equation:...
- Pentane (C5H12) is a component of gasoline that burns according to the following balanced equation: C5H12(l ) ...
- Use standard enthalpies of formation to calculate ΔH °rxn for each reaction. d. Cr2O3(s) + 3 CO( g)¡2 Cr(s) ...
- Use standard enthalpies of formation to calculate ΔH °rxn for each reaction. c. 3 NO2( g) + H2O(l )¡2 HNO3(a...
- Use standard enthalpies of formation to calculate ΔH °rxn for each reaction. a. C2H4( g) + H2( g)¡C2H6( g)
- Use standard enthalpies of formation to calculate ΔH °rxn for each reaction. a. 2 H2S( g) + 3 O2( g)¡2 H2O(l )...
- Use standard enthalpies of formation to calculate ΔH °rxn for each reaction. b. SO2( g) + 12 O2( g)¡SO3( g)
- Ethanol (C2H5OH) can be made from the fermentation of crops and has been used as a fuel additive to gasoline. ...
- Top fuel dragsters and funny cars burn nitromethane as fuel according to the balanced combustion equation: 2 C...
- The explosive nitroglycerin (C3H5N3O9) decomposes rapidly upon ignition or sudden impact according to the bala...
- Methanol (CH3OH) has been suggested as a fuel to replace gasoline. Find ΔH °rxn, and determine the mass of car...
- All the oxides of nitrogen have positive values of ΔGf° at 298 K, but only one common oxide of nitrogen has a ...
- The standard enthalpies of formation of gaseous propyne 1C3H42, propylene 1C3H62, and propane 1C3H82 are +18...
- The standard enthalpies of formation of gaseous propyne 1C3H42, propylene 1C3H62, and propane 1C3H82 are +185....
- It is interesting to compare the 'fuel value' of a hydrocarbon in a hypothetical world where oxygen is not the...
- What is a compound's standard heat of formation?
- Use standard enthalpies of formation to calculate the standard change in enthalpy for the melting of ice. (The...
- Calculate ∆H°f in kJ/mol for benzene, C6H6, from the following data: 2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(...
- Acetylene 1C2H22 and nitrogen 1N22 both contain a triple bond, but they differ greatly in their chemical prop...
- Hydrogen and methanol have both been proposed as alternatives to hydrocarbon fuels. To compare the energy of t...
- Hydrogen and methanol have both been proposed as alternatives to hydrocarbon fuels. Which fuel contains the mo...
- Acetic acid (CH3CO2H), whose aqueous solutions are known as vinegar, is prepared by reaction of ethyl alcohol ...
- Styrene (C8H8), the precursor of polystyrene polymers, has a standard heat of combustion of -4395 kJ/mol. Writ...
- Under certain nonstandard conditions, oxidation by O2( g) of 1 mol of SO2( g) to SO3( g) absorbs 89.5 kJ. The ...
- Methyl tert-butyl ether (MTBE), C5H12O, a gasoline additive used to boost octane ratings, has ΔH°f = -313.6 kJ...
- Methyl tert-butyl ether (MTBE) is prepared by reaciton of methanol (l) (ΔH°f = -239.2 kJ/mol) with 2-methyl-pr...
- Given the standard heats of formation shown in Appendix B, what is ΔH° in kilojoules for the reaciton CaCO3(s)...
- The ΔH for the oxidation of sulfur in the gas phase to SO3 is -204 kJ/mol and for the oxidation of SO2 to SO3 ...
- Given the standard heats of formation shown in Appendix B, what is ΔH° in kilojoules for the reaciton 3 N2O4(g...
- When magnesium metal is burned in air (Figure 3.6), two products are produced. One is magnesium oxide, MgO. T...
- Calcualte ΔH° in kilojoules for the synthesis of lime (CaO) from limestone (CaCO3), the key step in the manufa...
- Use the information in Table 9.2 to calculate ΔH° in kilojoules for the photosynthesis of glucose (C6H12O6) an...
- Use the data in Appendix B to find standard enthalpies of reaction in kilojoules for the following processes: ...
- Use the data in Appendix B to find standard enthalpies of reaction in kilojoules for the following processes: ...
- Use the data in Appendix B to find standard enthalpies of reaction in kilojoules for the following processes: ...
- Isooctane, C8H18, is the component of gasoline from which the term octane rating derives (b) The standard mola...
- The mechanism for the oxidation of HBr by O2 to form 2 H2O and Br2 is shown in Exercise 14.74. (a) Calculate t...
- Consider the following acid-neutralization reactions involving the strong base NaOH(aq): HNO31aq2 + NaOH1aq2¡N...
- The methane molecule, CH4, has the geometry shown in Figure 2.17. Imagine a hypothetical process in which the ...
- One of the best-selling light, or low-calorie, beers is 4.2% alcohol by volume and a 355-mL serving contains 1...
- Employing the bond enthalpy values listed in Table 8.4, estimate the molar enthalpy change occurring upon (c) ...
- Metallic mercury is obtained by heating the mineral cinnabar (HgS) in air: HgS1s2 + O21g2 S Hg1l2 + SO21g2 (a)...
- Methanol 1CH3OH2 is made industrially in two steps from CO and H2. It is so cheap to make that it is being con...
- Methanol 1CH3OH2 is made industrially in two steps from CO and H2. It is so cheap to make that it is being con...
- Small molecules with C'C double bonds, called monomers, can join with one another to form long chain molecules...
- When a gaseous compound X containing only C, H, and O is burned in O2, 1 volume of the unknown gas reacts with...
- Combustion analysis of 0.1500 g of methyl tert-butyl ether, an octane booster used in gasoline, gave 0.3744 g...
- Acid spills are often neutralized with sodium carbonate or sodium hydrogen carbonate. For neutralization of ac...
- (b) Use the data in Appendix B to calculate ΔH° for the reaction of potassium metal with water.
- Calculate the enthalpy of the reaction 2NO(g) + O2(g) → 2NO2(g) given the following reactions and enthalpies o...
- What is the isobaric heat of combustion for ethane, C2H6(g), in kJ per mole of ethane at 298.15 k?
- How much energy is required to decompose 765 g of PCl3
- What is the heat of combustion of ethane, C2H6, in kilojoules per mole of ethane? Enthalpy of formation values...
- Use standard enthalpies of formation to calculate δh∘rxn for the following reaction: 2 H2S(g) + 3 O2(g)→ 2 H2O...
- Calculate the enthalpy of the reaction 2NO(g) + O2(g) → 2NO2(g)
- Use the molar bond enthalpy data in the table to estimate the value of δ𝐻°rxn for the equation C2H4(g) + HBr(...
- Use standard enthalpies of formation to calculate δh∘rxn for the following reaction: Cao(s) + CO2(g) → CaCO3(s...
- Calculate the enthalpy change for the reaction P4O6(s)+2 O2(g) → P4O10(s)
- For which one of the following is the enthalpy of the reaction the same as the enthalpy of formation?
- Use the molar bond enthalpy data in the table to estimate the value of δ𝐻∘rxn for the equation
- Use the values of δhf° in appendix 4 to calculate δh° for the following reactions.
- For which one of the following reactions is δh°rxn equal to the heat of formation of the product?
- Use the standard reaction enthalpies given below to determine δh°rxn for the following reaction:
- Calculate the heat evolved per mole on combustion of each substance to yield co2(g) and h2o(g).
- Calculate δs∘rxn for the following reaction. the δs∘ for each species is shown below the reaction.
- Calculate delta h for the following reaction
- Calculate the enthalpy of the reaction 2NO(g) + O2(g) → 2NO2(g) given the following reactions and enthalpies o...
- Using the table below, estimate δh for the "water splitting reaction": H2O(g) → H2(g) + 12 O2(g).
- Which answer best describes the transfer of heat that occurs when 1.20 mol of H2 reacts?
- Which answer best describes the transfer of heat that occurs when 1.70 mol of H2 reacts?
- Which answer best describes the transfer of heat that occurs when 1.40 mol of H2 reacts?
- Given the following at 25°C, calculate ΔHf for HCN(g) (in kJ/mol) at 25°C.
- In many ways, hydrogen as a biofuel compares very favorably to ethanol and other fuels.
- Which answer best describes the transfer of heat that occurs when 1.30 mol of H2 reacts?
- 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)
- What is the change in enthalpy associated with the combustion of 530 g of methane (CH4)?
- The enthalpy of the reaction is –2,840 kJ. What is the heat of combustion, per mole, of glucose?