Ch 17: Thermochemistry Flashcards
Heat always flows from a ______ object to a ______ object.
warmer–>cooler
A system gains heat in a ___________ process and loses heat in an __________ process.
endothermic
exothermic
Heat flow is measured with two common units, the _______ and the _____.
calorie
joule
The heat capacity of an object depends on both its ____ and its ________ ___________.
mass
chemical composition
In calorimetry, the heat released by a system ______ the heat absorbed by its surroundings.
Conversely, the heat absorbed by a system equals the heat released by its ____________.
equals
surroundings
The ________ change for a reaction can be treated like any other reactant or product.
enthalpy
The heat ________ by a melting sold is exactly the same as the heat lost when the liquid solidifies;
that is, ∆H___ = -∆H_____.
absorbed
∆Hfus
∆Hsolid
The heat absorbed by a vaporizing liquid is exactly the same as the heat lost when the vapor _________;
that is, ∆H___ = -∆H____.
condenses
∆Hvap
∆Hcond
Heat is either _________ or ________ during the formation of a solution.
released or absorbed
Energy is the ability to __ ____ or ______ ____.
do work or create heat
The Law of Conservation of Energy states…
Energy neither created or lost in a chemical reaction.
What is the energy stored in a substance because of its composition?
Potential energy
What is a form of energy that flows from a higher temperature to an object of a lower temperature?
Heat
What is the amount of heat required to raise the temperature of one gram of water one degree Celsius?
Calorie
The SI unit of heat is…
Joule
The ________ ____ of a substance is the amount of heat required to raise the temperature of one gram of the substance by one degree of Celsius.
specific heat
What is the energy of motion?
Kinetic energy
What is the Kelvin temperature of a substance a measure of?
The average kinetic energy of particles in a sample.
What is the specific part of the universe that contains the reaction or process that you wish to study or focus upon?
System
The ___________ is everything else in the universe except the system.
Surroundings
What is an insulated device used to measure the absorption or release of heat in chemical or physical processes?
Calorimeter
What is a process or reaction that absorbs heat (i.e. gains heat)?
Endothermic
What is a process or reaction that releases heat (i.e. loses heat)?
Exothermic
An exothermic process causes the temperature of the surroundings to ____ __.
heat up
The symbol used to express change is _ , called _____.
∆
delta
A negative sign for heat or work indicates __________ _______.
exothermic process
One calorie is equal to _____ joules.
4.184
The name of the lowest possible temperature is ________ ____ and is equal to _______ degrees Celsius.
absolute zero
-273.15
What is the mathematical equation that relates the tmerpature change of a substance with the amount of heat energy absorbed by the substance?
C = q / M X ∆T
One food calorie (with a capital C) is equal to how many calories?
1,000
_____ have more PE than liquids or solids.
Gases
Breaking a bond take how much energy?
A lot
_____ can be used to find the enthalpy of a reaction.
Water
Qsystem =
-Qsurroundings
-Qsurroundings =
Qsystem
-Qrxn =
Qwater
swater X mwater X ∆Twater =
Qwater
In Qwater=swater X mwater X ∆Twater, what does s stand for?
specific heat
In Qwater=swater X mwater X ∆Twater, what does m stand for?
mass
In Qwater=swater X mwater X ∆Twater, what does ∆T stand for?
change in temperature
1 Calorie = _ kilocalorie = ____ calories
1 kilocalorie
1000 calories
