Energy Changes Flashcards
(7 cards)
What is an exothermic reaction?
Energy is given to surroundings during bond making in products.
What is an endothermic reaction?
Energy is absorbed from the surroundings to break bonds. Decreasing temperature.
What variables can affect temperature change in exothermic and endothermic reactions?
Pressure, the presence of a catalyst and the amount of reactants.
When do exothermic reactions occur?
Energy released when bonds are formed in products is used to break bonds in reactants.
When do endothermic reactions occur?
When more energy is required to break existing bonds in the reactants than are released when new bonds are formed in the products.
How does teperature change depending on volume?
The more solution, the greater the volume for energy to spread out.
Why is a polystyrene cup with a lid used when investigating temperature change?
To reduce any heat losses. Polystyrene is a good thermal insulator. The lid reduces heat loss to the air.
