Term
| What three things happen in any chemical reaction? |
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Definition
Reactaants are consumed
Products are formed
There is a transfer of energy |
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Term
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Definition
| The study of the changes in energy and transfer of energy that accompanies physical and chemical processes. |
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Term
| What are the three Laws of Thermodynamics? |
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Definition
1st Law: Conservation of Energy
2nd Law: Law of Entropy
3rd Law: Law of Absolute Zero |
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Term
State the First Law of Thermodynamics.
(Law of Conservation of Energy) |
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Definition
This law suggest that energy can be transferred from one system to another in many forms but the energy cannot be created or destroyed.
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Term
State the Second Law of Thermodynamics.
(Law of Entropy) |
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Definition
| Heat cannot be transfered from a cold body to a hot body. As a result of this fact of thermodynamics, natural processes that involve energy transfer must have one direction, and all natural processes are irreversible. |
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Term
State the Third Law of Thermodynamics
(Law of Absolute Zero) |
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Definition
| The third law of thermodynamics states that if all the thermal motion of molecucule (kinetic energy) could be removed, a state called absolute zero would occur. Absolute zero results in a Temperature of 0 Kelvins or -273.15° Celcius. |
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Term
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Definition
| The capacity(ability) to do work. |
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Term
| What are the units associated with Energy? |
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Definition
joule (J)
kilojoule (kJ)
calorie (cal)
kilocalorie (kcal)
Note: calorie is denoted with a lower case "c" |
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Term
What are the different forms of Energy?
How can Energy manifest itself? |
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Definition
Mechanical (car)
Electrical (electricity)
Radiant (light)
Nuclear
Chemical (hot/cold packs) |
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Term
| State the formula of Work and the unit associated with it. |
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Definition
Work = Force * Distance
Unit is joule (J)
or
Newton*meter (1N*m=1J)
Note: Work and Energy have the same unit. |
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Term
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Definition
A measure of the internal energy that is absorbed or transferred from one body to another.
Represented by a lower case q.
(Not to be confused with Temperature) |
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Term
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Definition
| A relative measure of hotness or coldness. |
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Term
Define:
Internal Energy (U or E) |
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Definition
| The total kinetic energy and potential energy of all the molecules or an object. |
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Term
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Definition
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Term
| State the formula for determining Kinetic Energy. |
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Definition
KE=1/2mv2
Kinetic Energy=1/2 mass * velocity squared
Note:
All molecules and atoms are in constant motion so KEatom/molecule is >0 |
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Term
| State the formula for determing Potential Energy. |
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Definition
PEgrav=mgh
m=mass
g=gravity
h=height |
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Term
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Definition
| Energy possessed by an object due to its postition or composition. |
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Term
| What are some examples of Potential Energy? |
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Definition
Gravitational
Tension or Compression(elastic)
Centrifigal
Magnetic |
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Term
| What is the formula for determing Internal Energy? |
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Definition
ΔU=q+w
Change of Internal Energy(ΔU) = heat + work
Note:
Internal Energy may be represented
by U or E
so you might see ΔU or ΔE in a problem. |
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Term
| How may Energy(E) be transfered? |
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Definition
In the form of heat
In the form of work
In the form of work and heat |
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Term
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Definition
Substances under investigation
Ex: Chemical reaction occuring in a beaker |
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Term
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Definition
The rest of the universe.
Every not being investigated. |
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Term
Define:
Universe
(Not the Carl Sagan type) |
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Definition
| System plus its surroundings. |
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Term
Define:
Thermodynamic State of a System |
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Definition
A set of conditions that describe and define a system.
i.e.
1. number of moles or each substance
2.physical state of each substance
3. temperature
4. pressure
5. volume |
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Term
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Definition
A property of a system that depends only on hte current state of the system and not how the system came to be in that state.
An Indepent property. |
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Term
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Definition
Enthalpy is the quantity of heat necessary to raise the temperature of a substance from one point to a higher temperature.
Enthalpy represented by H |
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Term
| State the formula for determining Enthalpy(H). |
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Definition
H = U + PV
Enthalpy = Internal Change + Pressure*Volume |
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Term
Define:
Enthalpy Change(ΔH) |
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Definition
| The change in the heat content of a system that accompanies a process which occures at a constant pressure. |
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Term
What are the aliases associated with
Enthalpy Change(ΔH)? |
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Definition
Enthalpy Change(ΔH)
=
Heat change
=
Heat of reaction |
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Term
| State the formula for determing Enthalpy Change(ΔH). |
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Definition
ΔH = Hfinal system - Hinitial system = qp
Note:
qp= qconstant pressure
subscript p = constant pressure |
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Term
| What are the units associated with Enthalpy Change(ΔH)? |
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Definition
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Term
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Definition
The process of a system absorbing heat from its surroundings.
Endothermic = Enter |
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Term
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Definition
The process of a system releasing heat into its surroundings.
Exothermic = Exit |
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Term
| If an endothermic/exothermic process occures at a constant pressure what is ΔH equal to? |
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Definition
qp
Note:
exothermic = negative qp = negative ΔH
endothermic = positive qp = positive ΔH |
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Term
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Definition
| Experimental technique used to measure the heat released or absorbed during a reaction. |
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Term
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Definition
| A device used to measure the heat released/absorbed during a reaction. |
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Term
Define:
Calorimeter Constant |
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Definition
The amount of heat gained by a calorimeter.
aka: the Heat Capacity of the Calorimeter.
Unit: J/oC |
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Term
State the formula for determing the calculation heat released/absorbed by a system.
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Definition
q=mcΔT
heat(J) = mass(g) * specific heat(J/g-oC) * ΔTemp
ΔT = Tfinal - Tinitial
pg 17 chap 5 .ppt |
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Term
Define:
Specific Heat(J/g - oC) |
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Definition
The amount of heat needed to increase the temperature of 1 gram of material by 1oC.
varies by substance
depents on the state of the substance
always a positive number
pg 17 ch5 .ppt |
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