C6-The Rate and Extent of Chemical Changes Flashcards
(23 cards)
Reactant
A substance that reacts together with another substance to form products during a chemical reaction.
Product
A substance formed in a chemical reaction.
Particle
A general term for a small piece of matter. For example, protons, neutrons, electrons, atoms, ions or molecules.
Activation energy
The minimum amount of energy that colliding particles must have for them to react.
Successful collision
A collision between reactant particles that has enough energy for a reaction to happen.
Surface area
The total area of all sides on a 3D shape.
What do particles need to do in order to react together?
Collide with enough energy
Catalyst
A substance that changes the rate of a chemical reaction without being changed by the reaction itself.
Frequency
The total number of times an event occurs.
Gradient
Another word for steepness. On a graph, the gradient is defined as being the change in the ‘y’ value divided by the change in the ‘x’ value. It defines how steep a line is.
Tangent
A straight line that just touches a point on a curve.
Enzyme
A protein which catalyses or speeds up a chemical reaction.
Reaction pathway
The sequence of reactions needed to produce a desired product from a particular set of raw materials.
Reversible reaction
A chemical reaction in which the products can change back into the reactants.
Equilibrium
In chemical reactions, a situation where the forward and backward reactions happen at the same rate, and the concentrations of the substances stay the same.
What does the rate of a chemical reaction tell us?
How quickly a product is formed or how quickly a reactant is used up.
Rate of reaction equation
reactant used/product formed
time taken
Factors that effect the rate of a chemcial reaction
Concentration / pressure
Catalyst
Surface area
Temperature
Benefits of catalysts
Only small mass of catalyst is needed
Remains unchanged at the end of the reaction
Same amount of product in shorter time
Lower temperature to lower energy costs
Drawbacks of catalysts
Specific to one single catalyst
Ways to measure the rate of reaction
Precipitation and colour change
Change in mass
Volume of gas given off
How do you calculate gradient?
change in Y / change in X
How do you calculate relative atomic mass?
sum of (isotope abundance x isotope mass no.) / sum of all abundances of all the isotopes
