Energy Basics
This type of energy is energy of motion
Kinetic Energy
Which type of reaction releases energy?
Exothermic
What does the y-axis represent on an energy diagram?
Energy (kJ)
What is activation energy?
Energy needed to start a reaction
What is the system in a chemical reaction?
The reaction taking place
This type of energy is stored energy based on position or arrangement
Potential Energy
Which type of reaction absorbs energy from the surroundings?
Endothermic
What does the peak of the curve represent?
Activation energy
What does a catalyst do to the activation energy of a reaction?
It lowers the activation energy
In an exothermic reaction, where does energy flow? Include words of system and surroundings.
From the system to the surroundings
As temperature increases, what happens to the average kinetic energy of particles?
Kinetic energy increases
In an exothermic reaction, are products at higher or lower energy than reactants?
Lower energy
What is the difference between reactants and products called on a diagram?
Heat of Reaction (ΔH)
True or False: A catalyst lowers the activation energy and helps change an endothermic reaction to exothermic
False
In an endothermic reaction, where does energy flow? Include words of system and surroundings.
From the surroundings to the system
If particles are moving slower, what can you say about their kinetic energy and temperature?
They both decrease
Why does an endothermic reaction feel cold?
It absorbs energy from the surroundings
How can you identify an exothermic reaction from a diagram?
Products are lower than reactants
True or false: A catalyst lowers the activation energy of a chemical reaction and therefore speeds the reaction up.
True
A reaction causes the temperature of the surroundings to increase. Is it endo or exothermic? Explain.
Exothermic because surroundings temperature increased due to released energy
Explain how kinetic and potential energy change during a chemical reaction.
Kinetic energy allows particles to collide; potential energy changes as bonds break (increase) and form (decrease).
Compare kinetic and potential energy changes in endothermic vs exothermic reactions.
Endothermic: PE increases, KE decreases
Exothermic: PE decreases, KE increases
Draw how an endothermic diagram differs from an exothermic diagram.
Endothermic: products higher than reactants; Exothermic: products lower than reactants
How does lowering activation energy affect reaction rate?
Reaction moves faster
A reaction is taking place in a water bath, and the water bath rises in temperature by 20 degrees. Is the reaction endothermic or exothermic?
Exothermic