c8 - rates, equilibrium and organic chemistry

what does the rate of a chemical reaction tell you?

how fast reactants turn into products

name a fast reaction

chemicals inside a firework exploding

name a slow reaction

iron rusting

what are the two ways you can work out the rate of a chemical reaction?

find out how quickly:
- reactants are used up as they make products
- the products of the reaction are made

how to calculate the rate of a reaction at a certain time?

chek page 128 in textbook for tangent method

what are the two mean rates of reaction formulae

mean rate of reaction = quantity of reactant used / time OR quantity of product formed / time

what are the five main factors that affect the rate of chemical reactions?

• temperature
  - surface area of solids
  - concentration of solutions
  - pressure of gases
  - if there is a catalyst present

only when can reactions take place

when the particles (atoms, ions or molecules) of reactants come together

explain collision theory

reacting partcles do not only have to bump into each other but also need to collide with enough energy to cause a reaction

what is the amount of energy needed for a reaction called?

activation energy

what can we do to make a reaction more likely to happen?

• increase the frequency of reactant particles colliding with each other
  - increase the energy they have when they collide

how does surface area affect reaction rate?

higher SA = higher reaction rate as there are more particles on the outside layer to be collided with

why is a higher concentration good for a quicker reaction?

more particles to collide with

why is high gas pressure good for faster reactions?

as the particles are closer together for faster reactions

how does raising the temperature help reactions?

• more frequent collisions
  - particles collide with more energy

whats more effective in a reaction : Ea or frequent collisions

an increased proportion of particles exceeding the activation energy has a greater effect on rate than increased frequency of collisions

how do catalysts work?

they provide an alternate reaction pathway with a lower activation energy

what do catalysts remain during the reaction?

chemically unchanged

what is good about industrial catalysts

• increases rate of reaction
  - reduces cost

what is a reversible reaction?

a chemical reaction where the products can react to reform the original reactants, allowing the reaction to proceed in both forward and backward directions

anhydrous meaning

"""without water"""

in reversible one reaction is {{c1::exothermic}} and the other is {{c2::endothermic}}

in equilibrium in a reversible reaction what happens

the rate of forward and backward reactions are equal

{{c1::image-occlusion:rect:left=.0124:top=.3312:width=.0295:height=.275:oi=1}}
{{c2::image-occlusion:rect:left=.4829:top=.9348:width=.0812:height=.0464:oi=1}}

""

le chatelier's principle

if a system at equilibrium is subjected to a change in conditions, the equilibrium will shift to counteract that change.

le chatelier is basically all of c8.9

increase x and the system counteracts by increasing y, therefore the reaction where y is the product has the higher yield

you can change in a reversible reaction to change equilibrium

temperature, pressure or concentration