chapter 9 Flashcards
If it has more energy, does it make it less or more stable?
less stable
thermochemistry definition
absorption or release of heat energy that accompanies chemical reactions
if it has less energy, is it more or less stable
it is more stable
define energy
capacity to do work or supply heat (kinetic or potential)
define joule
SI unit for energy
What is kinetic energy
energy of motion
What is potential energy
stored energy
conservation of energy law
energy can’t be created or destroyed, only be converted into another form
define temperature
thermal energy (kinetic) of molecular motion
define heat
amount of thermal energy transferred from one object to another as a result in a temp difference between the two.
what is the first law in thermodynamics
energy can’t be created or destroyed, only converted from one to another.
define system
starting reactants and final products of the experiment
define surroundings
everything but the system (EX: flask, solvent, room)
define internal energy
sum of all kinetic and potential energies for every molecule, in the system of an isolated system
is it possible to completely isolate a chemical reaction from its surroundings
no
How do you calculate internal energy
energy final minus energy initial
if energy flows from a system to its surroundings, is it positive or negative?
negative
internal energy depends on what?
identity, pressure, size, state, temperature
if energy flows from its surroundings to a system, is it positive or negative?
positive
state function
property whose value depends only on present state, condition, not path to get there.
energy content in food is measure in?
calories
define work
fore that produced movement times distance the object moved.
thermal chemical equation
chemical equation with enthalpy change
what is enthalpy change
amount heat released or absorbed when reactants convert to products
