Saunders Hess Laws Lab Report

SCH 4U1HESS’S LAW: POST ACTIVITY REFLECTION & EXIT CARD
Instructions: Please fill out one per group as you complete the Hess’s Law discovery activity
1.
List any conclusions you made by analyzing the reactions (reactants, products and enthalpy) and looking at
the hints.
2. Explain how you might solve the problem below based on the discoveries you made during this activity.
Note: You do not actually have to solve the problem, just explain the process.
1.
C(s) + O2(g) —> CO2(g)
ΔH̊ = -394 kJ
2. H2(g) + ½O2(g) —> H2O(l)
ΔH̊ = -286 kJ
3. CH4(g) + 2O2(g) —> CO2(g) +
2H2O(l)
What is the heat of formation for CH4?
C(s)
+
2H2(g) —>
ΔH̊ = -891 kJ
CH4(g)
ΔH̊= ?
3. After the follow- up lesson on Hess’s Law calculate the enthalpy of formation for methane using the
information in question 2.