RATE OF CHEMICAL REACTIONS
There are multiple ways that the rate of a chemical reaction can be changed. The rate of a chemical reaction is the speed the reaction happens in. For example, if you were to bake a cake at a high temperature, it would bake quicker than if you set the oven at a lower temperature. This has to do with the collision theory. What's that? The collision theory says that for a chemical reaction to happen, the reactants must make contact and collide! There are a variety of methods of how a chemical reaction can either be sped up or slowed down. There are approximately 5 ways the rate of a chemical reaction can be changed.
Temperature - One of the most common ways scientists use to change the rate of a reaction is to increase or decrease the temperature of the reactants when performing an experiment. How does this even work you may ask, this is because of the energy of the particles! A particle is a very small part of something, like legos in a lego building. One particle is equal to one lego. Basically, the higher temperature means higher energy, which creates more collisions. This is because more energy means more movement, which makes the particles bump into each other more. This results in more chemical reactions.
Surface Area - Surface Area is one of the ways that the rate of a reaction can be changed. Have you ever wondered why Mum chops up the potatoes before she boils them? Or why Dad uses spoons of sugar instead of sugar cubes? This is all because of the surface area. The surface area allows the particles to collide more. The reason a spoon of sugar is better than a sugar cube is that it dissolves in the water quicker. This is because the more water touches the sugar as it has a higher surface area.
Agitation - Agitation is used to affect the rate of a reaction. A perfect example is when you mix your tea when you add sugar. Why? Well, it makes the sugar dissolve quicker. If you don't mix the sugar, it takes longer to dissolve. This makes the rate of reaction higher as the agitation of the reactants make sure that the particles are constantly colliding. If the materials aren't mixed, sometimes a substance can form and create a layer between the two reactants. Like if you don't mix the sugar, a gooey layer of watery sugar will form in between the water and the sugar.
Concentration and Pressure - Concentration and pressure are how many particles in a certain space there are. To put it simply, a cup of tea with 3 spoons of sugar has a higher concentration of sugar than a cup of tea with 1 spoon of sugar would. The concentration and pressure of a reactant affect the rate of reaction as more particles mean more collisions, creating more reactions. The same goes for pressure, the only difference is that concentration is for liquids such as water, and pressure is for gases like the air.
Catalysts - Catalysts is a more complicated way of changing the rate of a reaction. Catalysts help with chemical reactions by reducing the amount of energy needed for a collision to occur. The easiest way to understand is that a catalyst is like a minister at a wedding ceremony, the minister causes the ceremony to take place, plays a role in determining how fast the ceremony takes place, and is not himself permanently changed as a result of the ceremony. When catalysts are used, they are not destroyed, meaning they can be used over and over again.
