R1.1 Flashcards
Define Temperature
Temperature is the measure of average kinetic energy of the particles
Define Heat
Is the measure of the energy content of a substance
Define Enthalpy
The total chemical energy inside a substance
How is enthalpy represented
🔺H
How do you know if a reaction is exothermic
When the products have less enthalpy than the reactants
What happens to the temperature in surroundings and systems in an exothermic reaction
temperature of the surroundings increases
temperature of the system decreases
In an exothermic reaction there is an enthalpy decrease so🔺H is
negative
What is it called if the rate is too slow and the reaction may not occur
reaction is kinetically controlled
When is a reaction endothermic
when the products have more enthalpy than the reactants
What happens to the temperature of the system and the surroundings in an endothermic reaction
The temperature of the surroundings decreases
The temperature of the system increases
In an endothermic reaction there is an enthalpy increase so 🔺H is
positive
What is the transition state stage
at which chemical bonds are partially broken and formed
Where is transition state located on the energy profile
higher in energy than recatants and products
Where is the EA arrow drawn from
from reactants to transition state
What are the reactants energy in exothermic reaction
reactants are higher in energy than the products
What reaction has a lower EA
Exothermic reactions
What are the reactants energy like in endothermic reactions
Reactants are lower in energy than the products
What reactions have a higher (longer arrow) EA?
Endothermic
Define accuracy
how close you got to the accepted results
Define Reliability
how close your results were to eachother
Define Precision
how many decimals places your measurements were made to
bond enthalpies are
average values
define standard enthalpy change of a reaction
the heat change in a reaction carried out at standard conditions
What is meant by lattice enthalpy
The amount of energy required to completely separate one mole of the solid ionic compounds into constituent gaseous ions
Definition of BE
Enthalpy change when one mole of covalent bonds is broken down into its gaseous state
standard enthalpy change of formation
enthalpy change when 1 mole of a substance is formed from its constituent elements with all reactants and products in standard states under standard conditions
