Vocab
What is the minimum amount of energy required to start a chemical reaction?
Activation energy
What happens if you change the subscripts in a chemical equation?
It would change the identify of the molecule.
Name one example of an exergonic reaction.
The release of energy in the form of electricity.
Biological catalysts are called __________.
enzymes
What cannot be created or destroyed?
Mass
A new substance that is formed following a chemical reaction.
Product
What forms of energy are either released or absorbed during a chemical reaction?
Light, sound, thermal or electrical energy
When balancing a chemical equation, it is acceptable to change the __________ in the formula.
Coefficients
A reaction that occurs when a substance reacts with oxygen
combustion reaction
Products have different properties compared to ______.
reactants
A chemical reaction that absorbs heat.
Endothermic reaction
What two conditions must exist for molecules to react with one another?
1 - The molecules must have enough force to break the molecular bonds.
2 - The collisions must occur in a way that the unbound atoms are in the right position to bond with each other.
How are catalysts and inhibitors similar and different?
Catalysts are used to speed up the reaction rate and inhibitors are used to slow down or stop the reaction rate.
They are similar because they are not permanently changed after a reaction. They can be recovered and reused.
What is required to break chemical bonds?
Energy
Increasing the temperature generally __________ the reaction rate.
Increases
A substance that increases the reaction rate without being permanently changed.
catalyst
To increast the rate of reaction, what 3 factors must be increased?
Concentration of reactants, surface area, temperature
Why are exergonic reactions sometimes called spontaneous reactions?
reactant
A substance used to slow down or stop a chemical reaction.
Inhibitor
A chemical reaction that releases heat
Exothermic reaction
Why does powdered grain ignite at a faster rate than a solid grain block?
It has more exposed surface area.
What are the five indicators that a reaction has occured?
1 - color change
2- formation of a precipitate
3 - formation of a gas
4 - release of light or sound energy
5 - noticeable odor
To increase the reaction rate, you should __________ the concentration of the __________ in the rate-determining (slow) step.
increase, reactant
Why is the freezing of liquid water to form ice not a chemical reaction?
The water molecules are not transformed into a different substance. This is an example of a physical change.