Rate Of Chemical Change Flashcards
Mean rate of reaction=
Quantity of reactant used or product formed/ time taken
Units for rate of reaction
G/s or cm3/s
Rate of reaction depends on:
1) collision frequency
2) energy transferred during a collision
3) temperature
4) the presence of a catalyst
5) concentration of solution
6) pressure of gas
7) surface area
When you increase temperature…
Particles move faster, increasing collision frequency
The faster they move, the more energy they have to make the reaction
If solution is more concentrated…
There are more particles in the same volume of solution, increases collision frequency
If the pressure of gas is increased…
the same number of particles occupy a smaller space, increasing collision frequency
If one reactant is a solid, breaking it up into smaller pieces will…
Increase the surface area: volume ratio. This means that for the same volume of solid, particles around will have more area to work on
catalysts…
lower the activation energy needed for a reaction to take place by providing an alternative pathway
What are reversible reactions?
Chemical reactions where the products can react to produce the original reactants
The direction of reversible reactions can be changed by…
Changing the conditions
If a reversible reaction is exothermique in one direction…
Then it’s endothermic in the other
Equilibrium is reached when…
Forward and reverse reactions occur at exactly the same rate
Dynamic equilibrium?
If a reversible reaction is taking place in a closed system, d.e. happens when both forward and reverse reactions are taking place simultaneously and at the same rate of reaction
When equilibrium lies in the right…
conc. of products is greater than conc. of reactants
If equilibrium lies on the left…
The concentration of the reactants is greater than the products’
