SCH4UE-1 - Unit 1: Energy Rates & Changes
Studied by 0 people
Call with Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/47
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No study sessions yet.
48 Terms
Thermochemistry
The study of energy changes that occur alongside physical and chemical changes in matter
Energy
The ability to do work
The difference in potential energy of the bonds in the reactants vs the products is the same as…
the amount of energy released/absorbed in the reaction
System
The specific part of the universe that is of interest to the study
Surroundings
The remainder of the universe not part of the system
Open system
A system where both energy and matter can be exchanged with the surroundings
Closed system
A system where energy, but not matter, can be exchanged with the surroundings
Isolated system
A system where neither energy nor matter can be exchanged with the surroundings
Enthalpy
The sum of thermal energy in a system (potential and kinetic)
Enthalpy change (ΔH)
The change in heat between the system and the surroundings during a chemical reaction under constant pressure (per mole, q otherwise)
Exothermic reaction
A reaction that released energy to the surroundings, ΔH <0
Endothermic reactions
A reaction that absorbs energy from the surroundings, ΔH >0
Standard enthalpy of formation (ΔHf)
The enthalpy change that occurs when 1 mole of a compound is formed from its elements in their standard states
Standard state
The most stable form of a substance at SATP
Bond dissociation energy
The quantity of energy needed to break a certain covalent chemical bond
Hess's law
ΔH for a reaction can be written as the sum of values of ΔH for each individual step reaction
Calorimetry
The measurement of heat flowing in and out of a system
Calorimeter
The device used to measure the absorption/release of heat
Heat capacity
The amount of energy needed to raise the temperature of a substance by 1K or 1C
Molar heat capacity
The amount of energy needed to raise the temperature of 1 mole of a substance by 1K or 1C
Specific heat capacity
The amount of energy needed to raise the temperature of 1g of a substance by 1K or 1C
Specific heat equation
q=mcΔT
Density of water
1g/mL
Specific heat capacity of water
4.184 J/g*K
Mass equation
mass = volume * density
Molar enthalpy change (ΔHr)
The change in heat between 1 mol of a substance and the surroundings
Thermodynamics
The study of the relationship between heat, work, and other forms of energy
Chemical kinetics
The study of reaction rates
Reaction rate
The change in concentration of a reactant/product over time
Equimolar
When the #moles of a reactant equal the #moles of a product
Differential rate law
The rate of reaction in terms of the changes in concentration of reactants over a time interval
Integrated rate law
The rate of reaction in terms of initial concentration and measured concentration after a given amount of time
Overall order of reaction
Sum of the orders of the reactants
Average rate of reaction
The average change in concentration per unit time over a given time interval (SECANT)
Instantaneous rate of reaction
The rate of a reaction at a particular point in time (TANGENT)
Chemical property
The behaviour of a pure subsance when it undergoes a chemical change/reaction
Phase
The physical state of matter of a substance
Catalyst
A substance that changes the rate of a reaction without being changed itself
Heterogenous catalyst
A catalyst existing in a different state from the reactants
Homogenous catalyst
A catalyst existing in the same state as the reactants
Rate law
rate=k[R]^m
Collision theory
Molecules can only react if they collide with one another
Activation energy
The minimum amount of energy required for a reaction to go through
Activation complex
An unstable arrangement of atoms found at the top of the potential energy "hill" during the transition state
Reaction mechanism
The sequence of events describing the process by which reactants become products
Elementary reaction
A step in a reaction mechanism where reactants react to directly form products
Intermediate
A species that appears in a reaction mechanism of a complex reaction, but not in the overall balanced equation
Molecularity
The number of molecules involved in a chemical process
Note 
Flashcards (21)