ENERGTICS Flashcards
What is enthalpy?
When a chemical reaction occurs when there is normally a change in energy
What is enthalpy change of reaction?
the heat change in a reaction at constant pressure
What is endothermic?
Reactions that absorb energy from the surroundings
What is endothermic?
Releasing energy to the surroundings
What is calorimetry
Used to work out the enthalpy change of combustion
What is exothermic?
Reaction that release energy to the surroundings
when bonds are formed
Change in energy is negative if more energy is released when bonds are formed than what was needed to break initial bonds the reaction will be exothermic
When bonds are broken?
Change in time is positive if more energy is needed to break bonds than energy given out when bonds are formed , reactions will be endothermic
Calorimetry experiement
- Polystyrene cup to prevent heat loss
2 . Add acid first measure temperature - Then add alkali/ solid , stir and measure temperature change
What is hess law
The total enthalpy change of a reaction is independent of the value take
What is standard enthalpy of combustion
The enthalpy change when one mole of a substance is completely burned oxygen under standard conditions with all substance in their standard states
What is enthalpy of formation?
The enthalpy change is when a substance is formed from its elements under standard conditions and with all substances in that standard states.
