6.1 Endothermic and Exothermic Processes

If work is done by a system, is it exothermic or endothermic?

Exothermic

If work is done on a system, is it exothermic or endothermic?

Endothermic

If it is exothermic, does temperature increase or decrease?

Increase

If it is endothermic, does temperature increase or decrease?

Decrease

Is going from solid to gas exothermic or endothermic?

Endothermic

Is going from gas to solid exothermic or endothermic?

Exothermic

What is it called when solid changes into gas?

Sublimation

What is it called when gas changes into solid?

Deposition

Which state has the highest energy?

Gas state

What do temperature changes in a system indicate?

Energy changes

What can energy changes in a system be described as?

Endothermic and exothermic processes

Examples of energy changes in a system that can be described as endothermic and exothermic processes:

Heating or cooling of a substance, phase changes, chemical transformations

What happens to the energy of a system when a chemical reaction occurs?

Decreases, increases, or remains the same

If energy of the system decreases, is it exothermic or endothermic?

Exothermic

If energy of the system increases, is it exothermic or endothermic?

Endothermic

What happens to the energy lost by the reacting species (system) for exothermic reactions?

Gained by the surroundings

For exothermic reactions, how do surroundings gain energy?

By heat transfer from or work done by system

For endothermic reactions, how does the system gain energy from surroundings?

By heat transfer to or work done on the system

Is the formation of a solution an exothermic or endothermic process?

Either one of the two

Whether the formation of a solution is an exothermic or endothermic process depends on what?

Relative strengths of intermolecular/interparticle interactions before and after the dissolution process