Chemistry 1128 Self Test
enthalpy change for the overall reaction is the same as the sum of enthalpy changes for all the steps in the reaction
Hess's law
transitional structure that results from an effective collision and persists while old bonds are breaking and new bonds are forming
activated complex
energy required to transform reactants into an activated complex
activation energy
broken when energy is applied
chemical bonds
set of assumptions regarding molecular collisions and reactions
collision theory
Energy can be neither created nor destroyed, but it can be ...
converted
We cannot measure energy, but we can measure its ...
effects
A change in energy is ... if the change is positive
endothermic
Reversible reactions contain an exothermic reaction going one direction and ... reaction going the other direction
endothermic
must be applied to break chemical bonds and released when the bonds are formed
energy
By plotting an energy pathway, the ... change and the activation energy in both a forward and reverse reaction can be determined
enthalpy
Reactants with low... tend to remain unreactive
enthalpy
... is the randomness, or disorder, of a system
entropy
Enthalpy and ...work together to provide the driving force for chemical reactions
entropy
Changes in concentration or pressure and adding a catalyst do not affect the ... constant
equilibrium
Concentration changes of reactants of products have no effect on the ... constant
equilibrium
The point at which the reactant and product concentrations undergo no further changes is called the ...
equilibrium
Enthalpy of ... is the enthalpy change involved in production a mole of compound
formation
Change in enthalpy minus the product of the Kelvin temperature and the entropy change is called ...
free energy
... is the type of energy lost due to friction during energy conversion
heat
Exothermic means that ... is released
heat
When ice absorbs heat and melts, its enthalpy ...
increases
between the breaking of reactant chemical bonds and formation of product chemical bond
intermediate steps
energy of motion
kinetic energy
A system is a sample of ... and energy under observation
matter
The law of conservation of matter and energy states that the amount of energy and ... in the universe is constant
matter
Combustion reactions usually proceed faster if placed in a ... gas environment
oxygen
energy of position or state
potential energy
Concentration of reactants can affect the ... of reaction in a chemical system
rate
According to the first law of thermodynamics, in a chemical reaction the mass of the ... equals the mass of the products
reactants
step-by-step sequence of reactions by which the overall chemical change occurs
reaction mechanism
A negative enthalpy of formation means heat is ... by the formation of a compound
released
If the products remain longer in a transitional state during a ... reaction, less products are converted to reactions
reverse
The reference point for chemical reactions is called the ... state
standard
affects equilibrium constant
temperature
study of heat energy changes that accompany chemical reactions
thermochemistry
transfer of heat
thermodynamics
An object traveling along the ground has ... (amount) gravitational potential energy as it relates to the ground
zero
