| why does increasing temp increase the rate of reactions | the particles have more energy so they can overcome the activation energy barrier and collide more successfully and frequently |
| what does collision theory state | chemical reactions can only take place when the reacting particles collide with each other and collisions must have sufficient energy |
| what is the rate of reaction determined by | the frequency of successful collisions |
| what happens to the rate of reaction when the concentration increases | the rate of reaction increases as the number of successful collisions is higher, the rate is directly proportional to concentration |
| why do we get more product at the end of the reaction when concentration is increased | we had more reactant molecules at the start so more product is made |
| why does increased surface area actually increase the rate of reaction | the particles in a solution only react with the particles on the surface of the solid so an increased surface are means there's more collisions/s and the rate of reaction increases |
| explain surface area in terms of surface area to volume ratio | smaller sized blocks of solid react and have a greater surface area to volume ratio than larger blocks therefore more particles on the surface and more collisions/s |
| describe an experiment you can do to measure the affect surface area has on rate of reaction | -marble chips in HCl produces carbon dioxide
-carbon dioxide can be collected in a gas syringe and measure the volume or measure the mass decrease as CO2 leaves through cotton wool
-change the surface area of the marble chips and repeat |
| why is cotton wool used | to allow the CO2 to pass through but also to stop any hcl from splashing out of the conical flask and decreasing the mass causing an anomalous result |
| what is the activation energy | the minimum amount of energy particles must have in order to react and collide successfully |
| why does increasing temp increase the rate of reactions | the particles have more energy so they can overcome the activation energy barrier and collide more successfully/s |
