Rates Of Reaction Flashcards
List the factors that affect the rate of reaction
Temperature
Concentration
Pressure
Surface area
Catalyst
What must happen for a chemical reaction to take place?
The particles must collide with sufficient energy to react. Known as activation energy
How does an increased surface are increase the rate of reaction?
-more reactant particles are exposed at the surface.
-the frequency of successful collisions between the reactant particles increases
- the rate of reaction therefore increases
How does an increased temp increase the rate of reaction?
The energy of particles increases therefore the reactant particles move more quickly
This increases the frequency of successful collisions between reactant particles
(As well as particles colliding with more energy)
The rate of reaction increases
How does why does SA increase rate of reaction?
More reactant particles are exposed at the surface
The frequency of collisions between reactant particles increases
The rate of reaction increases
How does a catalyst increase the rate of reaction?
Lowers activation energy creating an alternative path for the reaction this increases the rate of reaction
How does an increased pressure increase the rate of reaction?
When the pressure of a gas increases it means the same number of particles are occupied in a smaller space therefore particles collide more frequently increasing the rate of reaction.
How to measure rate of reaction?
Rate of reaction=amount of reactant used or amount of product formed/ time
How does an increased concentration increase the rate of reaction?
There are more reactant particles in a fixed volume. The particles collide successfully more frequently, increasing the rate of reaction.
Rates of reaction practice disappearing cross experiment
Using a measuring cylinder place 10cm ^3 of sodium
thiosulfate into a conical taste.
- Place conical flask onto black cross
-using a measuring cylinder add 10cm^3 of Hcl
into the conical flask.
-swirl the solution and start the stop clock
. After a certain time the solution will become
cloudy
-stop stop clock when the cross can no longer
be seen
Repeat using different concentrations such as a 1m 0.5 of hcl
repeat whole investigation and calculate a mean
What does le Chattleirs principle state
If a system is at equilibrium and a change is
made to the conditions, then the system
responds to counteract the change.
Hager process equation
Nitrogen+hydrogen ⇌ ammonia
Remember Iron catalyst is above symbol
N2(g)+3H2(g) ⇌ 2NH3(g)
Numbers at end of equation are small and on lower half
Where do raw materials from Hager process come from
Nitrogen=air
Hydrogen = reaction methane with steam
Conditions for Haber process to produce ammonia
- Decrease temp to shift reaction to right as forward is exothermic
however this makes the reaction slow
450°C is a compromise temp as it creates a relatively fast reaction and a relatively high yield of ammonia
. High pressure is used as equilibrium will shift right
