Rate and extent of chemical change Flashcards
(13 cards)
The rate of a chemical reaction is how
Fast the reactants are changed into products
Graphs can show you how the rate of a reaction changes if there is a steep line on a graph it means
The faster the rate of reaction
What is the collision theory
Is that a reaction will only take place when particles collide
what is activation energy
The minimum amount of energy for reaction needs to react
The rate of a reaction can depend on four things
Temperature concentration surface area and whether a catalyst is used
Increasing the temperature can increase the rate this means that particles move faster this also means that they
Have more energy and more collisions
If a solution is more concentrated it has more particles in the same volume this means
The collisions between reactant particles are more frequent
Increasing surface area increases the rate for example if one of the reactants is a solid breaking it up into smaller pieces will increase its surface area this means
More of the solid particles are available to particles of the other reactant so more collisions will happen
A catalyst is something that speeds up a reaction catalysts work by
Providing a different pathway for a reaction
Practical: measuring rate of reaction using marble chips and hydrochloric acid which react to produce carbon dioxide gas
Measure out the volume of dilute hydrochloric acid using a measuring cylinder
Pour it into a conical flask
Measure out the mass of marble chips
Add more chips to the flask and quickly attach a delivery tube and a gas syringe to the flask
Start a stopwatch and watch the gas start to collect in the gas syringe
As reactants react their concentrations fall as more products are made the backward reaction will speed up after a while the forward reaction and backward reaction will be gone at exactly the same rate this system is at
Equilibrium
The one piece of equipment you could use to measure the volume of gas given off in a reaction
A mass balance
