Question

The standard state molar enthalpy of reaction for the formation of water as both a liquid and a gas have been measured: H_2 (g)+1⁄2 O_2 (g) → H_2 O (l) ∆H^(∘ )= -285.83 kJ⁄mol H_2 O H_2 (g)+1⁄2 O_2 (g) → H_2 O (g) ∆H^(∘ )= -241.82 kJ⁄mol H_2 O Use these data and Hess’s law to calculate ∆H^(∘ ) for the following reaction: H_2 O (l)→ H_2 O (g

Answer 1

Answer:

The standard enthalpy of formation of carbon monoxide is -99 kJ/mol. C(s) +½O₂(g) → CO(g); ΔH=? To solve this problem, we use Hess's Law. Our target equation has CO(g) on the right hand side, so we reverse equation 2 and divide by 2