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Hess's Law

Q. Calculate AH2.980 (in kJ) for the process P(s) + 5/2 Cl2(g) -> PCI5(g) from the following information. P(s) + 3/2 Cl2(g) -> PCI3(g) AH2980 0 = -287 kJPCI3(g) + Cl2(g) -' PCI5(g) AH298 = -88 kJ

Solved • Jul 18, 2019

Hess's Law

Q. Consider these reactions, where M represents a generic metal. 2M(s)+6HCl(aq)⟶2MCl3(aq)+3H2(g) Δ𝐻1=−622.0 kJ HCl(g)⟶HCl(aq) Δ𝐻2=−74.8 kJ H2(g)+Cl2(g)⟶2HCl(g) Δ𝐻3=−1845.0 kJ MCl3(s)⟶MCl3(aq) Δ𝐻4=−372.0 kJ Use the given information to determine the enthalpy of the reaction 2M(s)+3Cl2(g)⟶2MCl3(s)

Solved • Jul 13, 2019

Hess's Law

Q. Given that H2(g)+F2(g)⟶2HF(g) Δ𝐻∘rxn=−546.6 kJ 2H2(g)+O2(g)⟶2H2O(l) Δ𝐻∘rxn=−571.6 kJ calculate the value of Δ𝐻∘rxn for 2F2(g)+2H2O(l)⟶4HF(g)+O2(g)

Solved • Jul 12, 2019

Hess's Law

Q. Using the following thermochemical data: 2Ho (s) + 6HF (g) → 2HoF3 (s) + 3H2 (g) ∆rH° = -1787.4 kJ/mol-rxn 2Ho (s) + 6HCl (g) → 2HoCl3 (s) + 3H2 (g) ∆rH° = -1457.0 kJ/mol-rxn calculate ∆rH°, for the following reaction: HoF3(s) + 3HCl (g) → HoCl3 (s) + 3HF (g)

Solved • Jul 9, 2019

Hess's Law

Q. Using the following thermochemical data, calculate Δ H f° of Cr 2O 3( s). 2CrCl 3( s) + 3H 2O( l) → Cr 2O 3( s) + 6HCl( g) H° = 276.9 kJ/mol 2Cr( s) + 3Cl 2( g) → 2CrCl 3( s) H° = –1113.0 kJ/mol 4HCl( g) + O 2( g) → 2Cl 2( g) + 2H 2O( l) H° = –202.4 kJ/mol A. 633.7 kJ/mol B. –1187.5 kJ/mol C. –1038.5 kJ/mol D. –1139.7 kJ/mol E. 1592.3 kJ/mol

Solved • Jul 7, 2019

Hess's Law

Q. Calculate [d]Hrxn for 2NOcl9g)---N2(g) + 02(g) + Cl2(g) Given the following set of reactions: 1/2 N2(g)+1/2 O2(g) --NO(g) [d}Hrxn = 90.3 kJ NO(g) + 1/2 Cl2(g) ---NOCl(g) [d]Hrxn - 38.6 Kj

Solved • Jun 28, 2019

Hess's Law

Q. Calculate ΔH˚rxn for the reaction FeO + CO → CO2 + Fe using the given information.

Solved • Jun 25, 2019