1.1 Rates of Reaction Flashcards
What are the 4 indications that a reaction has taken place?
- Colour change
- Effervescence
- Precipitation
- Energy/temperature change
What is a colour change?
The chemical changes colour as the reaction takes place
What is effervescence?
Bubbles of gas going through a liquid
What is precipitation?
A solid forming in a liquid
What is an energy/temperature change?
- Exothermic: an increase in temperature
- Endothermic: a decrease in temperature
What factors affect rates of reaction?
- Temperature
- Concentration
- Particle size
- Presence of a catalyst
How does temperature affect rate of reaction?
As temperature is increased, the energy in the particles and their speed increases. This means the higher the temperature, the higher the rate of reaction.
How does concentration affect rate of reaction?
As concentration increases, the number of collisions increases. This increases the rate of reaction.
How does particle size affect rate of reaction?
The smaller the particle size, the greater the total surface area. This means the rate of reaction increases.
How does a catalyst affect rate of reaction?
A catalyst is a chemical that speeds up the reaction but is not used up in the proccess.
How do you measure rate of reaction?
- Mass loss
- “Over water”
- Gas syringe
How do you measure rate of reaction using mass loss?
Set the experiment up on a balance and measure the change in mass
How do you measure rate of reaction “over water”?
The volume of gas is collected in a measuring cylinder through a water trough. This only works if the gas is insoluble in water.
How do you measure rate of reaction using a gas syringe?
The gas is collected in a gas syringe. This works if it is both soluble and insoluble.
How do you calculate average rate?
Average rate =
change in quantity
____________________
change in time
