enthalpy change and calorimetry Flashcards
What is a reaction system?
Anything that is involved in a reaction.
what is the sorroundings?
Everything sorrounding the reaction system.
What is an exothermic reaction, and describe it.
When a system gives out heat to its sorroundings.
As reaction progresses, the system loses energy.
The sorroundings get hotter, and the system gets colder.
What is an endothermic reaction?
When a reaction system takes in, or absorbs in heat from the sorroundings.
As the reaction progresses, the reaction system takes in energy.
The sorroundings get colder, and the system gets hotter.
what does the Y axis represent in an energy level diagram?
total energy ( in the system).
What does the X-axis represent in an energy level diagram?
progress of reaction.
Describe how an energy level diagram would look like for an exothermic reaction.
LOOK AT PAGE 103 FOR ANSWERS
Describe how an energy level diagram would look like for an endothermic reaction.
LOOK AT PAGE 103 FOR ANSWERS
What is the enthalpy change of a reaction?
the heat energy change of a reaction system , at a contstant pressure.
what type of enthalpy change do exothermic reactions have?
negative enthalpy change.
what type of enthalpy change do endothermic reactions have?
Positive enthalpy change.
What is the symbol for enthalpy change?
∆H
what unit do we use for enthalpy changes?
Joules ( J), which we then have to convert to KJ, by dividing by 1000.
what is specific heat capacity?
The ammount of energy required, in order to raise the temperature of one gram of a substance , by one kelvin.
what is the formula for the ammount of het energy given in, or taken out?
q = M x C x ∆T
