Given the following data: Na(g) + O2(g) O2(g) 2N20(g) → 2NO(g), AH = +180.7 kJ AH =-113.1 kJ 2NO(g) + 2NO2(g), 2N2(g) + O2(g), AH--163.2 kJ use Hess's law to calculate AH for the following reaction: N20(g) + NO2(g)→3NO(g) Express the enthalpy in kilojoules to four significant digits. ? AH = kJ

4. Hess's Law Calculate AH for the reaction: 2 C(s) + H2(g) → C:H2(g), given the following chemical equations and their respective enthalpy changes: C2H2(g)+02(g)→2CO2(g)+H20(1) AH, = -1299.6 kJ (1) %3D C(s)+02(g)→CO2(g) AH, = -393.5 kJ (2) H2(g)+502(g)→H20(1) AH3 = -285.8 kJ (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

Given the following reactions Reactions Enthalpies of Reaction 1 Na(s) + Cl2(8) → Na(g) + Cl(g) AH = 257 kJ 2 Na(g) + Cl(g) → Na*(g) + Cl(g) AH = 164 kJ 1 Cl2(g) → Nacl(s) Na(s) + AH = -333 kJ Use Hess' Law to determine the AH for the following reaction: (watch your states and charges) Na*(g) + Cl'(g) → NaCI(s) X kJ