Chapter 6 - Thermochemistry

Natural gas

________**: Associated with petroleum deposits, consists mostly of methane, but it also contains significant amounts of ethane, propane, and butane.

Hesss Law

Hints for using ________: Work backward from the required reaction, using the reactants and products to decide how to manipulate the other given reactions at your disposal.

variable composition

Coal has ________ depending on both its age and location.

constant pressure

At ________, exothermic means ▵H is negative; endothermic means ▵H is positive.

Syngas

________ can be used directly as a fuel and as a raw material to produce other fuels.

Attractive

________ and repulsive forces also lead to potential energy.

Constant pressure calorimetry

________ is used in determining the changes in enthalpy for reactions occurring in solutions.

Coal

________ was formed from the remains of plants that were buried and subjected to high pressure and heat over long periods of time.

Multiply reactions

________ to give the correct numbers of reactants and products.

▵H

________= q only at constant pressure.

state function

Enthalpy is a(n) ________, so we can invoke Hesss law and choose any convenient pathway from reactants to products and then sum the enthalpy changes along the chosen pathway.

Specific heat capacity

________**: The energy required to raise the temperature of one gram of a substance by one degree Celsius.

Thermodynamic quantities

________ always consist of two parts: a number, giving the magnitude of the change, and the sign, indicating the direction of flow.

Coal slurries

________ might replace solid coal and residual oil as fuels for electricity- generating power plants.

ideal gas

For a(n) ________, work can occur only when its volume changes.

▵H

________ is not dependent on the reaction side.

state function

Enthalpy is a(n) ________.