Thermodynamics Flashcards
The law of thermodynamics apply to the ___
universe
First law of thermodynamics
energy cannot be created or destroyed’ energy in a system remains constant but may be converted from one form to another
The amount of energy contained within a system
enthalpy
When heat transferred to the system
endothermic
When heat is given off to the environment
exothermic
In endothermic reaction, the products have ____ energy than the reactants
more
In exothermic reactions the products have ___ energy than the reactants
less
the transfer of heat via direct contact
conduction
the transfer of heat due to motion of a liquid or gas
convection
The transfer of heat via electromagnetic radiation
radiation
Used to determine whether an expansion or compression is happening
work
Under constant ____, heat and enthalpy within a system is a same (e.g in ___)
pressure, calorimetry
The amount of energy that is required to raise the temperature of 1.0 g of a substance by 1°C
specific heat capacity
The specific heat capacity for the same molecule depending on the ____, and is given by the formula ____. This means the the qsystem has to = ____. The heat required for a phase change, without changing the temperature is ____
phase, q = mc(delta T), -qsurroundings, q = m(delta H)
At a phase change, the ___ stays the same even though the __ __ increases. This is because any additional heat input is used to change the ___ not raise the temperature
temperature, heat energy, phase
A bomb calorimeter is used to measure the heat ___ by a sample ___ under a ___ atmosphere in a closed vessel surrounded by ___. The qreaction = ____, and qcal = ____
emitted, burned, oxygen, water, -qcal, c(delta T)
There are 3 ways to calculate the standard enthalpy change: through the __ ___, the enthalpies of ___, and ___ law
bond energies, formation, Hess’s
It takes energy to ___ a bond as atoms are in a __ __ state when they are not bonded
break, high energy
(bond energies) delta H = ______
sum of all bonds broken (reactants) - sum of all bonds formed (products)
the standard enthalpy of formation for an element in its standard state is always __
0
Says that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes
Hess’s law
The degree of disorder or randomness in a system
entropy
__, ___ molecules have more entropy as they have more ways to move around in a 3D space
large, complicated
Says that the entropy of the universe is always increasing
2nd law of thermodynamics
The second law of thermodynamics is why heat flows from ___ to ___. The thermal energy becomes more __ __ among the particles which allows for an ___ in the entropy of the particles
hot, cold, spread out, increase
says that the entropy of a pure crystalline substance at absolute zero temperature is zero
3rd law of thermodynamics
of the 3 states of matter, ___ has the highest entropy. When ___ increases, the entropy increases. ___ temperature increases entropy. If the total number of product molecules is __ than the total number of reactant molecules, the entropy increases
gas, dissolution, higher, greater
any process that occurs without the input of external energy
spontaneous reaction
All spontaneous processes produce an __ in the entropy of the universe
increase
In an exergonic reaction, energy is ___ to the surroundings and delta G is ___ 0. This means that the bonds formed are __ than the ones broken. The reaction is ___
released, <, stronger, spontaneous
In endergonic reactions, the energy is __ from the surroundings and delta G ___ 0. This means the bonds formed are ___ than the bonds broken. The reaction is ____
absorbed, >, weaker, nonspontaneous
When delta G is negative, Keq is ____ 1, and the __ are favored at equilibrium
> , products
When delta G is positive, the K ___ 1, and the ___ are favoured at equilibrium
<, reactants
When delta G is at 0, the K = ____ and the products and reactants are ___ ___ at equilibrium
1, equally favored
