Key Area 1: Rates of Reaction Flashcards
What type of reactions are explosions?
Fast
What type of reactions is rusting?
Slow
What are four factors that affect rate?
Increased Concentration (solution)
Increased Temperature
Decreased Particle size (solid)
Catalysts
What is a solute?
The solid being dissolved
What is a solvent?
The liquid that dissolves
What is a solution?
When a solute dissolves in a solvent
More particles in the same place means?
More collisions
More collisions means?
More effective collisions
Rate of reactions definition
The rate of a chemical reaction is a measure of how fast the reactants are being used up and how fast products are being made (speed at which CR takes place)
Average rate?
Change in quantity of reactant over time. Slows as reactant is used up.
Graphs, gradient?
Gradient at the start shows the rate
Graphs, end point?
Flat line at the end is the total volume of gas
How do you calculate the average rate?
Change in volume
over
Change in time
How do you write the units for average rate?
Cm cubed/ s
or
Cm cubed -1S
What is a catalyst?
A substance that speeds up a chemical reaction
Catalyst at the end of reaction, summary
Speeds up reaction
Chemically unchanged at the end
Mass stays the same
Reactants over time?
Go down, decrease
Products overtime?
Go up, increase
How do chemical reactions happen?
When the particles and reactants come together
What is temperature the measure of?
Kinetic energy
Temp, Turns?
Heat into kinetic energy
Temp, When they get hotter?
Move faster
Using what particles increase reaction rate?
Smaller
Increase what cause more collisions at surface?
Surface area
Examples of catalysts
Nickel, used for margarine from veg oil
Platinum used in car exhausts
Test for Oxygen
Relights a glowing splint
What do you measure to follow the progress of chemical reactions?
Changes in mass, volume and other quantitys can be measured
Graphs can be interpreted in terms of?
End-point of a reaction
quantity of product
quantity of reactant used
effect of changing conditions
The rate of a reaction can be shown to decrease over time by?
Calculating the average rate at different stages of the reaction.
