Rates of reaction & Energy changes Flashcards
How does surface area effect rate (marble chip practical)
Smaller chips = larger surface area = faster rate of reaction
How does increasing the concentration of hydrochloric acid effect rate (marble practical)
Grater concentration = grater number of particles in a given volume = faster rate
How is rate of reaction determined through reactants formed
amount of reactant used / time
How is rate of reaction determined through products formed
amount of product formed / time
How do you measure reactant used
if product is a gas, which will be given off, you can carry out the reaction on a set of weighing scales and measure
how much mass is lost
How do you measure product formed
if product is a gas, you can measure the volume of gas produced in a gas syringe
What is activation energy
the minimum amount of energy required for a chemical reaction to occur
How do reactions occur
When reacting particles collide with enough energy
How can you increase the rate of rection
- temperature
- pressure
- concentration
- surface area
- using a cataylst
How does increasing temperature increase rate of reaction
Increasing temperature = increasing kinetic energy of particles
Collide more frequently and energetically, more likely to reach activation energy
How does increasing pressure increase rate of reaction
Increases the number of particles in a given volume therefore increases frequency of collisions
How does increasing concentration increase rate of reaction
increases the number of particles in a given volume and so increases the frequency of collisions
How does increasing surface area increase rate of reaction
There is a greater chance of particles colliding, increases the frequency of successful collisions therefore increases the rate of reaction
How do you find the rate of reaction graphically
Draw tangents to curves and use the slope of the tangent as a measure of
the rate of reaction
What does the gradient equate to
rate of reaction
