What affects the rate of reaction?

Let’s start be thinking what exactly is a reaction. It takes place as an interaction between two or more particles. For that to happen, they must get close. Really close. And fast. Fast because otherwise they wouldn’t have enough energy to break the existing bonds. That is the (in)famous activation energy. You need to break something before you can use it. Sad but true. We can address both factors: if there is less space between particles, they will be closer to each other and much closer also more often. This “squeezing” them tighter has its physical name – it’s means the same as increasing the concentration. In terms of gas bodies we can also talks about the pressure. Higher pressure – higher rate How about the speed? Particles are in this respect no different to other classical bodies – the higher the speed the higher the energy. The kinetic energy of a system is called in this case the internal energy. How do you recognise a system with high energy? Guess – it’s hot! Increasing the temperature is another method of increasing the rate. There is more to that but let’s keep it for another time. And watch out – increasing rate works in both directions of the equilibrium, so you may end up with less product then you hoped for!