Chapter 7 Flashcards
energy is
capacity to do work
[work = action of force over distance]
heat is
energy flowing from hot to cold
kinetic energy is associated with
movement
Ex) thrown ball through the air
thermal energy is a form of
kinetic energy associated with atoms/molecules moving and colliding and rotating (in liquids and gases) as well as vibrating in all states
[all related to temperature]
Potential energy is associated with
position
-stored energy
-may require an outside source to release
ex) books on shelves
chemical energy is a form of
potential energy
-associated with positions of electrons - and nuclei +
thermodynamics is the general study of
energy and its interconversions
internal energy (E) is the sum of all
kinetic and potential energies of all particles that compose the system
[difficult to measure, easier to measure change in total energy]
Delta H is a measure of only the heat exchanged under
conditions of constant pressure
sweat evaporating from skin
Is the sweat endothermic or exothermic?
the skin is?
sweat is endothermic
skin is exothermic
WATER freezing in a freezer is
endothermic or exothermic?
exothermic
WOOD burning in a fire is
endothermic or exothermic?
exothermic
the burning of candle wax is-
exothermic
combustion of natural gas in a stove is-
exothermic
endothermic system have ____ delta E
positive
natural gas burning on a stove is
delta h is?
EXOTHERMIC
negative delta H
combustion is an ________ process
exothermic
isop. alcohol evaporating from skin is
endothermic (requires energy input)
Delta h = positive
water condensing from steam is
exothermic, delta H= negative
endothermic means
heat absorbed from surroundings
exothermic means
heat is released
what signs for Q and W when a system is doing work on the surroundings and gaining heat from surroundings?
+ Q, - W
an endothermic reaction has a ___ delta H, _____ heat from surroundings, and feels:
positive, absorbs, feels cold to touch
