Chemistry - Chapter 6: Thermochemistry

Types of Energy

joules (J)

Because of the direct connection between energy and work, energy is measured in the same unit as work: ____

Thermodynamics

branch of physics that studies the relationship between heat, work, temperature, and energy.

Thermochemistry

specifically focuses on the heat energy involved in chemical reactions and changes.

open system

exchanges mass and energy

closed system

exchanges energy but not mass

isolated system

exchanges neither mass nor energy

exothermic reaction

condensation is an example of which reaction?

exothermic reaction

combustion is an example of which reaction?

First Law of Thermodynamics

“Energy cannot be created nor destroyed.” By Rudolf Clausius

Yield

is the mass of a product made in a chemical reaction

actual yield

is the mass that is made in the chemical reaction.

it is the amount of product obtained when the reaction takes place.

theoretical yield

maximum mass that is possible to make from a given mass of reactants.

the maximum amount of product calculated using the balanced equation.

percent yield

calculated by comparing the theoretical yield with the actual yield in the chemical reaction.

PY = (AY/TY) * 100

formula for percent yield

Energy

capacity to do work or transfer heat

Mechanical Energy

When work is done to an object, it requires energy. That required energy is called ____

Thermal Energy

Internal motion of the atoms is called _______, because moving particles produce heat.

Thermal Energy

____ causes changes in temperature and phase of any form of matter.

Friction

Thermal Energy can be produced by ____

Chemical Energy

is the energy that is stored in chemical bonds.

absorbed

When chemical bonds are broken, energy is ____

released

When new chemical bonds are formed, energy is ___

Exothermic Reaction

reaction where energy is released from the system to the surroundings

Endothermic Reaction

reaction where energy is absorbed from the surroundings to the system

fuel

___ and food are forms of stored chemical energy.

Electrical Energy

____ results from moving charges; depending on whether the charges are moving or stored it can be a form of kinetic or potential energy.

Radiant Energy

____ results from the motion of the particles within atoms and usually travels in waves.

Sound Energy

____ is given off by a vibrating object. This energy travels through matter in the form of waves.

Energy Transformation

Changes in the form of energy are called ___

Mechanical Energy

In an electric motor, electromagnetic energy is converted to ____

Electromagnetic Energy

In a battery, chemical energy is converted into ___

Mechanical Energy

The ___ of a waterfall is converted to electrical energy in a generator.