Hess's Law Examples

Home | General Chemistry 1 | Enthalpy | Hess's Law Examples

Enthalpy Hard Video

C $_2$ H $_4$ + 6 F $_2$ $\longrightarrow$ 2 CF $_4$ + 4 HF

Find the $\triangle$ H of the above reaction given:

H $_2$ + F $_2$ $\longrightarrow$ 2 HF $\triangle$ H = -537 kJ

2 C + 2 H $_2$ $\longrightarrow$ C $_2$ H $_4$ $\triangle$ H = +52 kJ

CF $_4$ $\longrightarrow$ C + 2 F $_2$ $\triangle$ H = +680 kJ

Posted by Mike Pruitt a year ago

Related Problems

Enthalpy Problems

4 Fe(s) + 3O $_2$ (g) $\longrightarrow$ 2 Fe $_2$ O $_3$ (s) $\triangle$ H = -1640 kJ

How many kJ of heat can be produced from 50.0g iron?

Enthalpy Medium Video

Specific Heat Problems

A 25.0 g piece of metal is heated to 200.0 $^\circ$ C and placed in 30.0 g of 25.0 $^\circ$ C water. The temperature of the water rises to 41.0 $^\circ$ C. What is the specific heat of the metal?

Enthalpy Easy Video

Enthalpy of Formation

Find the enthalpy of reaction, $\triangle$ H $_{rxn}$ , for the combustion of sugar (there is usually a table of enthalpies of formation in the back of chemistry textbooks)

C $_6$ H $_{12}$ O $_6$ (s) + 6 O $_2$ (g) $\longrightarrow$ 6 CO $_2$ (g) + 6 H $_2$ O (l)

Enthalpy Medium Video