controlling the rate Flashcards
What is the collision theory?
for a chemical reaction to occur, react particles must collide
what is needed for a successful collision to occur?
collision geometry is correct
particles have the right amount of energy
what happens when you increase the concentration/pressure?
it increases the rate
more particles in the same space, more likely to collide
what happens if you change the particle size?
powders react faster than lumps
more pieces exposed of the surface, available to react
what is the link between increase in temp and activation energy?
particles have more kinetic energy
they will collide with greater force
what is the activation energy
minimum amount of kinetic energy
describe energy in gas?
don’t all have the same energy
exothermic reaction in reaction profiles
products have less energy than reactants
triangle H has a negative value, loss of the surroundings
endothermic reaction in reaction profiles
products have more energy than reactants
triangle h have a positive value, gain from surroundings
what is the activated complex
high energy, unstable arrangement of atoms
between reactant and products
what does a catalyst do to the activation energy
speeds up a chemical reaction without being used up
lowers the activation energy by forming bonds with reactants
more reactants now have the moin energy required to react
