Chapter 16: Reaction Energy Study Guide

Thermochemistry is the study of __ that accompany chemical reactions and physical changes.

the transfers of energy as heat

__ is a measure of the average kinetic energy of the particles in a sample of matter.

Temperature

The energy absorbed or released as heat in a chemical or physical change is measured in a __.

calorimeter

Heat change corresponds to a change in energy, while phase change corresponds to a change in energy.

kinetic; potential

The equation for calculating specific heat is __.

cp = q / (m x delta T)

If a mixture of hydrogen and oxygen is ignited, the reaction is __ because it releases energy.

exothermic

In thermochemical equations, when delta H is __, it indicates that energy is released.

negative

The process of forming a solution generally involves an increase in __.

entropy

Specific heat is measured under __ pressure conditions.

constant

The change in enthalpy, represented by delta H, is defined as __.

Hproducts - Hreactants

Entropy measures the __ of a system.

randomness

An example of an endothermic process is __.

melting.

Chemical reactions tend to proceed towards a __ energy state.

lower

The amount of energy transferred as heat during a temperature change depends on the nature of the changing temperature, the of the material, and the size of the __ change.

material; mass; temperature

Heat can be derived from the equation __.

q = cp x m x delta T

Thermochemical equations must include the physical states of reactants and products because they affect the __ of energy released or absorbed during a reaction.

amount