Rate Of Reaction Flashcards
What is rate of reaction?
The average rate of a reaction describes how quickly reactants are used or how quickly products are formed during a chemical reaction
Explain Collision theory ?
Reactant particles must collide with the correct energy and orientation for the reactants to form products
If these collisions are successful the existing bonds break to form new bonds in the products
What are the factors affecting reaction rate?
1.Nature of reactants
2.Pressure
3. Temperature
4. Catalyst
5. Surface area
How does the nature of reactants affect the rate of reaction?
Different substances have different chemical properties thus some react faster / slower than others
Eg. Ionic computer react faster than covalently bonded compunds
How does pressure affect the rate of reaction?
As the pressure increases, there will be a high amount of particles per unit volume of gas resulting in more successful collisions causing the rate of reaction to increase
How does temperature affect reaction rate ?
If temperature increases, the average kinetic energy of the particles will also increase resulting in then moving faster. This will increase the number of effective collisions increasing reaction rate
How does a catalyst affect reaction rate?
A catalyst lowers the activation energy required resulting in more effective collisions
How does surface area affect reaction rate?
The greater the surface area of a substance the greater the amount of collusions that can take place, resulting in an increased reaction rate
How are reactions that produce CO2 measured?
With lime water CA(OH)2 + H2O
How are reactions that produce H2 gas produced?
A lit splint is used, in the presence of hydrogen it immediately ignites
How are reactions that produce oxygen measured?
Hydrogen peroxide decomposes in the presence of manganese (IV) oxide catalyst to produce oxygen and water
How are reactions that produce a precipitate ( solid) measured?
The amount of precipitate formed in a period of time is used as a measure of reaction rate
How are reactions that have colour changes measured?
The faster the colour change, the father the reaction rate is
How are some reactions that produce gas measured with a solid as one of the reactants?
Mass is lost, the loss indicates the amount of gas that has been produced and has escaped from the reaction vessel only in an open system
