Consider the problem below: (Equation 1) 2 H2O(l) ---> 2 H2(g) + O2(g) ΔH = 571.6 kJ (Equation 2) N2O5(g) + H2O(l) ---> 2 HNO3(l) ΔH = -73.7 kJ (Equation 3) 2 H2(g) + 6 O2(g) + 2 N2(g) ---> 4 HNO3(l) ΔH = -696.4 kJ (Equation 4) 2 N2(g) + 5 O2(g) ---> 2 N2O5(g) ΔH = ??????? To find ΔH for equation 4 you must: Question 18 options: a flip equation 1 only b flip equation 2 only c flip equation 3 only d flip equation 1 and equation 2 only e flip equation 1 and equation 3 only f flip equation 2 and equation 3 only g flip no equation

Use the following data to calculate ΔHf for hexane, C6H14(ℓ). Include negative sign if appropriate.               C6H14(ℓ) +19/2 O2(g) → 6CO2(g) + 7H2O(ℓ)    ΔHrxn = -4198.4 kJ                   ΔHf  of CO2(g) = -393.5 kJ/mol          ΔHf  of H2O(ℓ) = -285.8 kJ/mol

Calcium carbonate can be decomposed upon applying heat with the following equation CaCO3(s)  →  CaO(s)  +  CO2(g)    ΔH = +179.5kJ How much heat will be needed to decompose 30 g of calcium carbonate?  AND What size container will be required (in L) to contain the carbon dioxide generated at 25ºC and 1.2 atm?

Compound ΔHf (kj/mol) C2H5OH(i) -277.6 H2O(i) -285.8 H2O(g) -241.8 CO2(g) -393.5 CO(g) -110.5 H2O2(i) -187.6 C3H8(g) -103.8 What is the ΔH for the following reaction? C2H5OH(i) + 3O2 (g) --> 2CO2(g) + 3H2O(i)

(b)  Calculate the enthalpy change for the reaction C(graphite) + 2 H2(g) → CH4(g) with the help of the enthalpy changes of the following reactions: C(graphite) + O2(g) → CO2(g) ∆H= -393.5 kJmol−1 H2(g) +1/2O2(g) → H2O(l) ∆H = -285.8 kJmol−1 CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) ∆H = -890.4 kJmol−1 The temperature is 25 ◦C in all instances.

Calculate AHO,xn for each of the following using data from Appendix B. (a) 2 H2S(g) + 3 02(g) → 2 SO2(g) + 2 H20(g) kJ (b) SiO2(s) + 4 HF(g) → SİF4(g) + 2 H20(/) kJ

Given the standard enthalpy changes for the following two reactions: (1) Sn(s) + Cl½(g)–SnCl½(s) AH° = -325.1 kJ (2) Sn(s) + 2C12(g)– →SNCI4(1) AH° = -511.3 kJ what is the standard enthalpy change for the reaction: (3) SNC1,(s) + Cl2(g)SnCl4(1) AH° = ? kJ

（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?