http://www.ck12.org Chapter 17. Thermochemistry
Problems
- Write the balanced chemical equation for the formation of one mole of solid sodium nitrite, NaNO 2 , from its
elements in their standard states. - Determine∆H for the reaction below.
- Given the heats of reaction for the following combustion reactions: Calculate the enthalpy of formation of
methanol from its elements, according to the following equation: - Find the enthalpy change for the reaction below for the formation of phosphorus pentachloride from its
elements. Use the thermochemical equations below. - Use standard heats of formation from the table above (Table17.3) to calculate the standard heat of reaction
for each of the following.
a. 2H 2 O 2 (l)→2H 2 O(l)+O 2 (g)
b. Fe 2 O 3 (s)+3CO(g)→2Fe(s)+3CO 2 (g)
c. C 2 H 5 OH(l)+3O 2 (g)→2CO 2 (g)+3H 2 O(l)
Further Reading / Supplemental Links
- Hess’sLaw, http://www.kentchemistry.com/aplinks/chapters/6thermochem/Hess.htm
- Hess’sLaw:ThePrincipleoftheConservationofEnergy, http://www.science.uwaterloo.ca/~cchieh/cact/c12
0/hess.html
Points to Consider
Chemical reactions proceed at a wide variety of speeds or rates. Some reactions happen almost instantly, as soon as
the reactants come into contact with one another, while other reactions may take years to reach completion.
- How do chemical reactions occur on the molecular level?
- What factors influence the rate of a chemical reaction?