Which of the following have standard enthalpies of formation values that are not zero: Ar(g), Br2(l),...

Which of the following have standard enthalpies of formation values that are not zero: Ar(g), Br₂(l), H(g), W(s), Hg(s), Li₂(g)? Explain.

When ammonia is formed according to the following equation:

®2 NH₃(g)

the standard enthalpy of reaction (as written) is -92.6 kJ/mol. If 25.4 kg of ammonia (NH₃) is formed under standard conditions, what is the enthalpy change? Is this reaction exothermic or endothermic? Explain.

Alcoholic fermentation is the process by which carbohydrates decompose into ethanol and carbon dioxide. The reaction is multi-step and complex, but the overall reaction is

®2 C₂H₅OH(l) + 2 CO₂(g)

Given that the standard enthalpies of formation are C₆H₁₂O₆(s) = -1274.5 kJ/mol, C₂H₅OH(l) = -277.0 kJ/mol, and CO₂(g) = -393.5 kJ/mol, calculate the standard enthalpy for the fermentation reaction.

Solutions

Expert Solution

Ans 1

The enthalpy of formation for a substance in natural state = 0

Because a naturally occured substance does not form from any other substance so they neither absorb nor release the energy.

Argon is a natural gas

standard enthalpy of formation of Ar(g) = 0

Bromine is a natural liquid

standard enthalpy of formation of Br2(l) = 0

H is a not the natural elemental state of hydrogen gas. It is formed by breaking down the H2 gas molecule, so it needs energy to form H(g).

standard enthalpy of formation of H(g) is not 0.

Tungsten (W) is a natural solid.

standard enthalpy of formation of W(s) = 0

Hg(s) is a not the natural elemental state of mercury. Natural state of mercury is liquid. Hg(s) is formed from Hg(l), so it releases energy to form Hg(s)

standard enthalpy of formation of Hg(s) is not 0.

Li(g) is a not the natural elemental state of lithium . Natural state of lithium is solud. Li(g) is formed from Li(s) so it absorbs energy to form Li2(g).

standard enthalpy of formation of Li2(g) is not 0.

Amanda K answered 1 year ago

Next > < Previous

Related Solutions

A.) the standard enthalpy of formation of the reaction C2H4(g)+H2O(l)=C2H5OH(l) B.) Use standard enthalpies of formation...

A.) the standard enthalpy of formation of the reaction C2H4(g)+H2O(l)=C2H5OH(l) B.) Use standard enthalpies of formation to calculate the standard enthalphy change of: the reaction of methane gas, CH4, with chlorine rine to form liquid chloroform, CHCl3. Gaseuous hydrogen chloridee is the other product. C.) Use standard enthalpies of formation to calculate the standard enthalphy change of PCl3(g)+HCl(g)=PCl5(g)+H2(g)

Q3. Standard enthalpies of formation for atomic oxygen and for ozone are given here: O(g), ΔfH°...

Q3. Standard enthalpies of formation for atomic oxygen and for ozone are given here: O(g), ΔfH° = 249.2 kJ mol-1. O3(g), ΔfH° = 142.7 kJ mol-1 For each of the reactions below, evaluate the standard reaction enthalpy (kJ mol-1) corresponding to the dissociation threshold, and therefore calculate the wavelength (nm) and state the “colour” of a photon with the minimum energy sufficient to achieve dissociation. (a) dissociation of molecular oxygen, O2(g). {numerical ans. 240 nm} (b) dissociation of ozone, O3(g),...

Calculate the heats of combustion for the following reactions from the standard enthalpies of formation listed...

Calculate the heats of combustion for the following reactions from the standard enthalpies of formation listed in Appendix 2 from your book. a. C2H4(g)+3O2(g)>2CO2(g)+2H2O(l) b. 2H2S(g)+3O2(g)>2H2O(l)+2SO2(g)

The standard enthalpies of formation of PbS(s), SO2(g) and PbO(s) are -98.3, -296.8. and -217.3kj mol...

The standard enthalpies of formation of PbS(s), SO2(g) and PbO(s) are -98.3, -296.8. and -217.3kj mol respectively. Calculate the reaction enthalpy for the roasting of PbS(s). PbS(s)+3O2(g)--->2SO2(g)+2PbO(s)

Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Express your answer...

Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Express your answer using four significant figures. Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: N2O4(g)+4H2(g)→N2(g)+4H2O(g) Express your answer using four significant figures.

Calculate the P values for which Br2(g) is in a corresponding state to Xe(g) at 328...

Calculate the P values for which Br2(g) is in a corresponding state to Xe(g) at 328 K and 73.2 bar .

The standard enthalpies of formation oxides of the fourth period eleemtns of the d block are...

The standard enthalpies of formation oxides of the fourth period eleemtns of the d block are as follows: TiO VO MnO FeO CoO NiO CuO ZnO -518 -431 -385 -264 -239 -241 -155 -348 a)write a general equation suitable for calculating the lattice energy of any of these oxides, based on theoritical data b)Find the lattice energies of TiO, CuO, and ZnO c) Overall the most dissimlar enthalpy values are those of TiO and CuO; the most dissimilar enthaly values...

Which of the following statements are FALSE? ΔGo > 0 for Br2(l) + 2 Hg(l) --->...

Which of the following statements are FALSE? ΔGo > 0 for Br2(l) + 2 Hg(l) ---> 2 Br-(aq) + Hg22+(aq). ΔGo < 0 for MnO2(s) + SO2(g) ---> Mn2+(aq) + SO42-(aq). The cell potential for Co(s)|Co2+(aq, 0.1 M)||Fe3+(aq, 1.5 M)|Fe2+(aq,1.5 M)|Pt(s) is less than 1.05 V. The cell potential for Co(s)|Co2+(aq, 1.5 M)||Fe3+(aq, 0.5 M)|Fe2+(aq, 0.1 M)|Pt(s) is greater than 1.05 V. The cell potential for Cu(s)|Cu2+(aq, 0.5 M)||Cl2(g, 2.0 atm)|Cl-(aq, 2.0 M)|Pt(s) is equal to 1.02 V.

Given the provided enthalpies of formation, calculate ΔH for the reaction shown. 2 H2 (g) +...

Given the provided enthalpies of formation, calculate ΔH for the reaction shown. 2 H2 (g) + O2 (g) → 2 H2O (g) ΔH = -483.6 kJ 3 O2 (g) → 2 O3 (g) ΔH = +285.4 kJ 6 H2 (g) + 2 O3 (g) → 6 H2O (g) ΔH = ?

Calculate the enthalpy of the reaction 2NO(g)+O2(g)?2NO2(g) given the following reactions and enthalpies of formation: 12N2(g)+O2(g)?NO2(g), ?H?A=33.2...

Calculate the enthalpy of the reaction 2NO(g)+O2(g)?2NO2(g) given the following reactions and enthalpies of formation: 12N2(g)+O2(g)?NO2(g), ?H?A=33.2 kJ 12N2(g)+12O2(g)?NO(g), ?H?B=90.2 kJ Express your answer with the appropriate units. ?H? = Part B Calculate the enthalpy of the reaction 4B(s)+3O2(g)?2B2O3(s) given the following pertinent information: B2O3(s)+3H2O(g)?3O2(g)+B2H6(g), ?H?A=+2035 kJ 2B(s)+3H2(g)?B2H6(g), ?H?B=+36 kJ H2(g)+12O2(g)?H2O(l), ?H?C=?285 kJ H2O(l)?H2O(g), ?H?D=+44 kJ Express your answer with the appropriate units. ?H? =

Subjects