C8 Rates And Equillibrium Flashcards
How can you find the rate of a chemical reaction
Monitoring the amount of reactants used up over time or by measuring the amount of products made over time
What does the gradient on any time graph show
The rate of reaction at the given time
How do you calculate the rate of reaction at a specific time on a graph
Draw the tangent to the curve, then calculate its gradient.
Relation between the rate of a chemical reaction and surface area
Increasing surface area increases the rate of reaction
What does it mean if the rate of reaction increases
The frequency of collisions between reacting particles will increase.
What does a 10°c rise do to the rate of reaction
It doubles it
What happens to the rate of reaction when temperature increase
-Particles collide more frequently
-Particles collide with more energy
Step 1 of the effect of concentration on rate of reaction
Fill the water trough with water, fill the measuring cylinder with water, and clamp the cylinder upside down in the water trough.
Step 2 of the effect of concentration on rate of reaction practical
Set up the conical flask, bung and delivery tube so that the exit of the delivery tube is under the measuring cylinder.
Step 3 of the effect of concentration on rate of reaction practical
Add 50 cm3 of 2 mol/dm3 hydrochloric acid into the conical flask.
Step 4 of the effect of concentration on rate of reaction practical
Add 1 g of marble chips into the conical flask, put the bung back into the flask as quickly as you can, and start the stopwatch.
Step 5 of the effect of concentration on rate of reaction practical
Record the volume of gas collected every 30 seconds for 10 minutes.
Step 6 of the effect of concentration on rate of reaction practical
Repeat steps 1 to 5, but in step 3 use different concentrations of acid:
• 1 mol/dm3 hydrochloric acid
• 0.5 mol/dm3 hydrochloric acid
• 0.25 mol/dm3 hydrochloric acid.
Try to ensure that the marble chips are the same size for all your experiments.
What does a catalyst do
Speed up the rate of a chemical reaction-different catalysts are needed for different reactions.
When are catalysts used in industry
To increase rates of reaction and reduce energy costs
How do catalysts not work
They don’t increase the frequency of collision or make collisions any more energetic.
How do catalysts work
They provide an alternative reaction pathway to the products
What happens in a reversible reaction
The products of the reaction can react to make the original reactants
What kind of reaction is a reversible reaction if it is in forwards reaction
Endothermic
What kind of reaction is a reversible reaction if it is in reverse reaction
Exothermic
Relation of energy transferred to the surroundings in a reversible reaction
Amount of energy transferred to the surroundings when the reaction goes in one direction is exactly equal to the energy transferred back when the reaction goes in the opposite direction
Enthalpy meaning
Heat energy
What happens at equilibrium
The rate of the forward reaction equals the rate of the reverse reaction
