Chapter 6 Flashcards
The capacity to do work is considered what?
Energy
The form of energy that flows between two samples because of their difference in temp is considered what?
Heat
Energy a motionless body has by virtue of its position is what energy?
Potential energy
The energy of motion is what energy?
Kinetic energy
Energy associated with relative positions of electrons and nuclei in atoms and molecules is what energy?
Chemical energy
The sum of the kinetic and potential energies of the particles making up a substance is what energy?
Internal energy (Eint)
What is the heat required to raise the temp of 1.00 g of water by 1.00 degree Celsius?
1 calorie
1000 calories = 1 ________.
Kilocalorie (Kcal)
1 Kilocalorie (Kcal) = 1 __________.
Food calorie
Kilowatt-hour (kWh) is the energy unit used for ____________.
Electricity
1 kilowatt-hour (kWh) = ____________ J.
3.60 x 10^6 J
What is the SI unit for energy?
Joule (J)
1 calorie = _______ J
4.184 Joules
The law of the conservation of energy states that the total energy of the universe is ____________.
Constant
The law of the conservation of energy states energy cannot be _________ nor _________.
Created
Destroyed
Energy may be converted to different forms, but the total quantity of energy does not __________.
Change
Energy is a ________ function. It depends only on the current state, not how you got there.
State
It’s not easy to measure exact amount of internal energy so we measure _________ in internal energy.
Changes
Another way to put the law of the conservation of energy is the total energy of a system and its surrounding is ____________.
Constant
A system in the conservation of energy is the substance being ___________ for energy.
Evaluated
The surrounding in the law of conservation of energy is everything outside of the system that can __________ energy with the system.
Exchange
In a system for the law of the conservation of mass, energy can flow ______ or _____ of the system.
Into
Out
Energy can flow into a system in one of what two ways?
Heat(q) or work(w)
In an energy system, a positive value means energy is going ______ the system.
Into
In an energy system a negative value means energy is __________ the system.
Leaving
The science of heat transfer is called what?
Thermodynamics
As heat increases, molecular motion __________ and vice versa.
Increases
Heat (q) is energy that flows into or out of a system due to a difference in ____________ between the system and its surroundings.
Temperature
When the system absorbs heat, the value of q is __________.
Positive
When heat flows out of the system the value of q is ___________.
Negative
In chemical reactions or physical changes heat can be absorbed or _________ by the system.
Evolved
If heat is absorbed into a system it’s a what process?
Endothermic process
If heat is evolved from a system the process is called what?
Exothermic process
Heat transfer in chemical processes is considered what?
Thermochemistry
Gas phase molecules have _________ kinetic energy.
Higher
A difference in temperature leads to a heat energy ____________.
Transfer
The heat lost or gained by a sample is related to the change in ____________ (triangle t) and the heat ____________ (c) of the sample.
Temperature
Capacity
The totally heat equation is what?
q=(c)(triangle t)
The amount of heat required to raise the temperature of the sample by 1 degree Celsius (or 1 degree Kelvin) is the what?
Heat capacity
What is the heat capacity units?
J/degrees Celsius or J/degrees K
The amount of heat needed to produce a 1 degree Celsius (or 1 Kelvin) temp change per gram of material is considered what?
Specific heat capacity
What is the specific heat capacity equation?
S=q(J)/m(g)•triangle t(Celsius)
Another form of the specific heat equation is what?
q=(S) x (m) x (triangle t)
The work most commonly done by chemical reactions is what?
Pressure-Volume
The work equation is what?
W = F x D
P=F/A so F=P x A so in the work equation substitute F for _________ to give us _________.
P x A
W = P x A x D
The final work equation is what?
w = (-P)(change in volume or triangle V)
What are the two energy exchange equations?
q = S • m • triangle t w = -P • triangle V
The change in internal energy (triangle E) measures all energy exchanged and is given by the equation:
triangle E = q + w
If we determine triangle t + triangle V we can calculate what?
triangle E (change in energy)
What is the equation for change in energy if using a constant volume?
triangle E = q • v
If all energy flowing into or out of the system is heat energy at a constant volume (qv) then what?
q system = -(q surroundings)
How do we measure heat of a reaction?
Use a calorimeter
A devise used to measure the heat absorbed or evolved during a physical or chemical change is what?
Calorimeter
The heat evolved by the reaction = heat absorbed by water + the ________________. (Surroundings)
Bomb calorimeter
q reaction = _________________
q rxn = -(q water + q bomb)
Most chemical reactions occur at a constant what?
Pressure
The heat transferred at constant pressure = _______
qp
qp = ____________ where H = enthalpy.
Triangle H
Triangle H = heat transferred at a constant ____________.
Pressure
Triangle H = H final - ___________.
H initial
If the H final is bigger than the H initial then the triangle H is positive and it is a ______________ process.
Endothermic
If the H final is less than the H initial the the triangle H is negative and it is a _______________ process.
Exothermic
Enthalpy is a _________ function. It’s value depends only on the state of the system and not how it got there.
State
A thermochemical equation includes a balanced chemical equation (with phase labels) and an __________ written after the equation.
Enthalpy
If a thermochemical equation is multiplied by a factor, the enthalpy of a reaction must be multiplied by the ________ factor.
Same
If a reaction is the sum of 2 or more reactions, the net enthalpy of the reaction is the sum of the enthalpy’s of the reactions. This is what law?
Hess’s Law
The sum of enthalpy’s along one path = the sum of enthalpy’s a long another _________.
Path
Volume, temperature, pressure, and energy are _________ functions.
State
You cannot measure absolute H. You can only measure _______.
Triangle H (Change in energy or enthalpy)
What label is measured under standard conditions when talking about enthalpy?
Triangle H degrees
What is the standard condition for enthalpy values in terms of pressure?
1 atm
What is the standard condition for enthalpy values in terms of concentration?
1 mol/liter
What is the standard condition for enthalpy values in terms of temperature?
Usually 25 degrees C
What is the standard condition for enthalpy values in terms of species?
Species are in standard states (C graphite, O2 is gas)
Triangle H degree f or the standard enthalpy of formation is what?
The enthalpy change when 1 mol of compound is formed from elements under standard conditions
By definition, standard enthalpy of formation is for elements in their ___________ states.
Standard
The enthalpy of the reaction = the sum of standard enthalpy of formation of the products - the sum of standard enthalpy of formation of the ______________.
Reactants
