AP Chemistry

Name: _________________________ THERMOCHEMISTRY WORKSHEET #2

1.

2.

Use the molar enthalpy of combustion values given for each substance below to write thermochemical equations, with ∆H as a term in the equation, for the complete combustion of: a) ethanol, ∆Hocomb = -1368 kJ/mol

b)

Carbon, ∆Hocomb = -394 kJ/mol

c)

ethyne, ∆Hocomb = -1300 kJ/mol

d)

propane, ∆Hocomb = -2220 kJ/mol

Write a thermochemical equation, including the molar enthalpy, for the decomposition of one mole of magnesium chloride into its elements. ∆Hof = -641.3 kJ/mol

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AP Chemistry

Name: _________________________

3.

Write thermochemical equations, including ∆H, for the formation of one mole of SO2(g) and one mole of SO3(g) from their elements. For SO2(g) ∆Hof = -296.8 kJ/mol and for SO3(g) ∆Hof = -395.7 kJ/mol

4.

Draw an enthalpy diagram for the formation of SO3(g) in question #3.

5.

Write thermochemical equations, including ∆H, for each of the following: a)

the vaporization of one mole of chloromethane, CH3Cl(l) ∆Hovap = 21.5 kJ/mol

b)

the solidification of one mole of water

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AP Chemistry 6.

7.

Name: _________________________

The combustion of methane is an exothermic process that releases 890.4 kJ of energy. a)

Write a balanced chemical equation for this reaction and include the enthalpy change as a term in the equation.

b)

Rewrite the equation using ∆H notation.

c)

Draw an enthalpy diagram for this reaction.

Nitrogen gas reacts with oxygen gas to produce dinitrogen monoxide gas. 2 N2(g) + O2(g) + 163.2 kJ  2 N2O(g) a)

Is the reaction endothermic or exothermic? Explain.

b)

Draw an enthalpy diagram for this formation reaction.

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AP Chemistry 8.

Name: _________________________

Consider this equation for a reaction that occurs in a catalytic converter of an automobile. 2 CO(g) + 2 NO(g) 

N2(g) + 2 CO2(g) + 746 kJ

a)

How much energy is released per mole of carbon dioxide gas produced?

b)

Rewrite the thermochemical equation using ∆H notation.

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