Chemistry C7 Flashcards
How do reactions take place?
Reactions don’t happen unless they are in contact, the particles need to get together.
Not all collisions are effective, state an example
Paper in a room is not burning as there isn’t enough energy, heat energy is missing.
Activation energy is measured in….
It is measured in Kilo Joules.
Activation energy
Reactions only occur if the particles have enough energy, the minimun amount of energy need to a start a reaction is called the activation energy.
The amount of activation energy is different for each reaction.
when there is activation energy, there is an effective collision.
The collision theory
Chemical reactions can only happen if reactant particles collide, with enough energy.
The rate of reaction
Formulas
The speed at which a chemical reaction takes place.
R. of R.= amount of reactant used/time
R. of R.= amount of product formed/time
Factors that affect the rate of reaction
- Concentration
- Temperature
- Catalysts
- Surface Area/Particles
CONCENTRATION
More particles in the same space means more collisions given-effective collision
if we double the concentration, we double the number of collisions.
TEMPERATURE
Particles turn heat energy form the increase in tempertaure into kinetic energy, so the hotter it gets, the faster they move, making them collide more often- effective collisions.
CATALYSTS
Catalysts reduce the activation energy needed for a reaction by offering a shorter route (alternative way) for the reaction to take. The less activation energy the more effective collisions-faster rate.
SURFACE AREA/PARTICLES SIZE
Using smaller particles increases the rate. The increase in S.A, allows more collisions at the surface- faster rate.
What are the subatomic particles in an atomic structure
protons
neutrons
electrons
What is a cation
When metals lose electrons, they become positive and therefore cations
What is an anion
When metals gain electrons, they become negative and therefore anions
What type of reactions are Redox reactions
They are reduction and oxidation reactions
