Chemistry combined science

• What does collision theory state?


  particles must collide with enough energy in order to react. the more collisions there are the faster the reaction is particles have to collide with enough energy for the collision to be successful.
• how does increasing the temperature increase the rate of reaction?


  When the temperature is increased the particles all move faster. If they’re moving faster, they’re going to collide more the faster they move the more energy they have, so more collisions will have enough energy to make the reactions happen.
• How does increasing concentration increase the rate of reaction?


  If the solution is more concentrated, it means there are more particles knocking about in the same volume of solvent, but the pressure of a gas is increased. It means the same number of particles occupy small space. This makes collisions between the reactant particles, more frequent
• how does using a catalyst increase the rate of reaction?


  A catalyst decreases activation energy needed for the reaction to occur. By doing this. They provide an alternative reaction pathway with a lower activation energy
• How can you check if a chemical reaction has happened?


  Colour change
• What is an endothermic reaction?


  When energy is taken in from the surroundings