Chemical reactions and catalysts VMA

What does chemical reactions always involve

It always has to involve a transfer of energy

What is an exothermic reaction

It is the release of heat energy to surroundings and the temperature incraeses

Why does exothermic reaction involve a rise of temperature

It is because energy is usually given out by heating

What are some examples of exothermic reaction

Combustion is one as it gives out a lot of energy and many neutralisation and oxidation reactions are exothermic too as well as dissolving salt in water and condensing and freezing

What are some everyday uses of exothermic reactions

Self-heating cans, hand warmers

What is an endothermic reaction

It is a reaction that absorbs heat energy from surroundings and the temperature decreases

What are Somme examples of an exothermic reaction

Thermal decomposition and melting and boiling and also dissolving some salt in water

What is an everyday use of endothermic reactions

Sports injury packs

What are cataylts

It is a substance that offers an alternate pathway with lower activation energy. it does not get used up in the reaction.

Do catalyst change after a chemical reaction

Catalyst come out the same as when they went in this means the catalyst can be reused

How do catalysts help chemical al reactions to get there energy to get started

Catalysts offers an alternate pathway requiring lower amount of minimum energy needed for a reaction to happen

What are some disadvantages to catalysts

They can be expensive to buy and different reactions use different catalysts so businesses can't get away with just buying one to use for everything they also need to be cleaned as they can be poisoned by impurities

What is an advantage of catalysts

By increasing the speed of the reaction and lowering the temperature needed they make the industrial reactions charter and increase the amount of product made in given time

The minimum amount of energy needed for colliding particles to react is called the

Activation energy

Catalysts permit reactions to proceed along a ___________energy path.

lower

What is the name given to a catalyst in the human body?

Enzyme

What has to happen before a reaction takes place?

Reacting molecules must collide with enough energy and right orientation

collision theory

For a reaction to occur, the particles must collide, they must collide with the appropriate orientation, and they must collide with sufficient energy.

Increasing concentration of reactants

increases the number particles in the solution, increases the number of collisions and increases the reaction rate

Increasing the surface area of the solute

Solution process occurs at the surface of the solute

Solution process is sped up if surface area is increased

The more finely the divided a substance is, the greater the surface area and increases the rate of reaction