Mg(s) + 1/2 O2(g) -> MgO(s). Determind the value of the standard enthalphy change for the reaction.  Mg(s) + 2 HCI(aq) -> MgCl2(aq) + H2(g). ∆Hrxn = -316 kJ mol-1 MgO(s) + 2 HCI(aq) -> MgCl2(aq) + H2O. ∆Hrxn = -45.7 kJ mol-1 H2(g) + 1/2 O2(g) -> H2O. ∆Hrxn = -286 kJ mol-1

Calculate the standard enthalpy change for the reaction at 25 C. Standard enthalpy of formation values can be found in this list of thermodynamic properties. 2 CH,OH(g) + 30,(g) → 2 CO,(g) + 4 H, O(g) 2 CO, (g) + 4 H,0(g) kJ AHixn %3|

Determine the enthalpy change, AH, in kJ, for the following reaction: CS2 (1) + 302 (g) --> CO₂ (g) + 2SO2 (g) given the following thermochemical equations: C(s) + O₂ (g) --> CO₂ (g) ΔΗ = 91.2 kJ S (s) + O₂ (g) --> SO₂ (g) ΔΗ = -382 kJ C(s) + 2S (g) --> CS₂ (1) Do not report units in your answer. Report your answer to one decimal place and include the correct sign in your answer. AH = 82.6 kJ

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction (show all work):              P4(g) + 10 Cl2(g)  →  4PCl5(s)             ΔH°rxn =  ? Given:               PCl5(s)  →  PCl3(g) + Cl2(g)                ΔH°rxn = +157 kJ              P4(g) + 6 Cl2(g)  →  4 PCl3(g)              ΔH°rxn = -1207 kJ

55. Does the standard enthalpy of formation of H2O(g) differ from ΔH° for the reaction 2H2(g)+O2(g)⟶2H2O(g)?

Which of the following reactions occuring at 25° C defines the standard enthalpy of formation (TriangleHf) of liquid water? - 2 H (g) + O (g) -> H2O (l) - H2O(g) + O (g) -> H2O (l) - H2 (g) + ½O2 (g) -> H2O (l) - 2 H2 (g) + O2 (g) -> 2 H2O (l)

（1）Consider the reaction: 2A (g) + 3 B (g) → 2 C (g)     ΔHrxn = +254.3 kJ What will be the enthalpy change (in kJ) if 0.471 mol B reacts in excess A?   （2）Consider the reaction: C (s) + O2 (g) → CO2 (g)     ΔHrxn = -393.5 kJ What mass of carbon (in g) must be reacted via this mechanism to release 581.2 kJ of heat?

The ΔHo reaction for the oxidation of ammonia4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g) is -905.2 kJ.Calculate ΔH̊ for ammonia. The standard enthalpies of formation are:NO(g) = +90.3 kJ/molH₂O(g) = -241.8 kJ/mol.

Determine the enthalpy change, AH, in kJ, for the following reaction: CS2 (1) + 302 (g) --> CO₂ (g) + 2SO₂ (g) given the following thermochemical equations: C (s) + O₂ (g) --> CO₂ (g) ΔΗ = 90.1 kJ S (s) + O₂ (g) --> SO₂ (g) ΔΗ = -352 kJ C (s) + 2S (g) --> CS₂ (1) ΔΗ = 86.5 kJ Do not report units in your answer. Report your answer to one decimal place and include the correct sign in your answer.

In a coffee cup calorimeter, 3.00 g of NaOH (molar mass 40.00g/mol) was mixed with 75.0 mL of 1.00M HNO3. If the initial temperature of the HNO3 was 31.3°C and the final temperature of the solution was 22.3°C, determine AH for the reaction in kJ/mol. NaOH(s) + HNO3(aq) ===> NaNO3(aq) + H2O) The density and the specific heat capacity of the resulting solution are 1.00 g/ml and 4.18 J/°C.g, respectively. Units do not need to be typed, simply enter the correct number. If the sign of AH is negative put a negative sign (-) in the answer. Answer: