From experiments, you know the following thermochemical equations:5C(s) + 6H2(g) →C5H12(g) ΔH1 = - 146.3 kJH2O (l) → H2O(g) ΔH2 = + 44 kJH2(g) + ½ O2 (g) → H2O(g) ΔH3 = - 241.8 kJCO2(g) → C(s) + O2(g) ΔH4 = +393.5 kJUse the information above to find the value of ΔH in the reaction below. C5H12(g) + 8O2(g) → 5CO2(g) + 6H2O(l) ΔH

Using Hess's Law to calculate net reaction enthalpy Nitric oxide (NO) can be formed from nitrogen, hydrogen and oxygen in two steps. In the first step, nitrogen and hydrogen react to form ammonia: N₂(g) + 3H₂(g) → 2NH3(g) In the second step, ammonia and oxygen react to form nitric oxide and water: 4 NH3(g) + 50₂(g) → 4NO(g) + 6H₂O(g) ΔΗ= - 905. kJ ΔΗ= - 92. kJ Calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. Round your answer to the nearest kJ. kJ X S

A chemist carefully measures the amount of heat needed to raise the temperature of a 1.98 kg sample of C4H₂O from -0.4 °C to 11.4 °C. The experiment shows that 4.18 × 10* J of heat are needed. What can the chemist report for the molar heat capacity of C4H₂O? Be sure your answer has the correct number of significant digits. J-mol -1 -1 ☐ x10

Given the following thermochemical equations P4(s) + 6C12(g) 4PCI3(g) AH = -2439 kJ/mol 4PCI5(g) → P4(s) + 10CI 2(g) AH = 3438 kJ/mol find the AH for the reaction below, PCI5(g) → PC|3(g) + Cl2(g) O A) +249.8 kJ/mol O B) +999 kJ/mol O C) -999 kJ/mol O D) -249.8 kJ/mol

Natural gas burns in air to form carbon dioxide and water, releasing heat. CH4(g) + O2(g) → CO2(g) + H2O(g)                                    ΔHorxn = -802.3 kJ What minimum mass of CH4 is required to heat 23g of water by 32oC? (Assume 100% heating efficiency.) Natural gas burns in air to form carbon dioxide and water, releasing heat. CH4(g) + O2(g) → CO2(g) + H2O(g)                                    ΔHorxn = -802.3 kJ What minimum mass of CH4 is required to heat 23g of water by 32oC? (Assume 100% heating efficiency.) 62 g 22.5 g 7.80 mg 61 mg 118 mg

3. Hydrazine, N2H4, is a colorless liquid used as a rocket fuel. What is the enthalpy change for the process in which hydrazine is formed from its elements? N2(g) + 2H2(g) → N2H4(l) Use the following reactions, enthalpy changes, and Hess’s Law N2H4(l) + O2(g) → N2(g) + 2H2O(l); ΔrH° = −622.2 kJ H2(g) + ½O2(g) → H2O(l); ΔrH° = −285.8 kJ

2 NO(g) N2(g) + O2(g)   H = -180.7 kJ 2 NO(g) + O2(g) 2 NO2(g)   H = -113.1 kJ 2 N2O(g) 2 N2(g) + O2(g)   H = -163.2 kJ Use Hess's law to calculate H for the reaction below.3 NO(g) N2O(g) + NO2(g)H = _____k J

If the following three thermochemical equations are added together, what is the resulting equation:2 XO2 (g) +2 CO (g) →→ 2 XO (g) + 2 CO2 (g)2 XO (g) + 2/3 CO2(g) →→ 2/3 X3O4 (s) + 2/3 CO (g)2/3 X3O4 (s) + 1/3 CO2 (g) →→ X2O3 (g) + 1/3 CO (g)     Question 17 options:   6 XO (g) + 2 CO2(g) →→ 2 X3O4 (s) + 2 CO (g)   2 XO2 (s) + CO (g) →→ X2O3 (s) + CO2 (g)   C (s) + 3 XO2 (g) →→ X3O4 (g) + CO2 (g)   2 X3O4 (s) + CO2 (g)  →→ 3 X2O3 (g) + CO (g)   CO (g) + XO2 (g) →→ XO (g) + CO2 (g)

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A chemist carefully measures the amount of heat needed to raise the temperature of a 0.57 kg sample of a pure substance from 18.0 °C to 35.9 °C. The experiment shows that 19. kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance? Round your answer to 2 significant digits. - 1 - 1 •K J. g x10