Speed of reaction

Gradient of graph

Speed of reaction at that point in time.

* Steepest = fastest

Factors affecting speed of reaction

* Particle size of solids
* Concentration of solutions
* Pressure of gases
* Temperature of reactants
* Use of Catalyst

Particle size of a solid

Powder having a **smaller particle size** than lumps has a **larger total surface area** for the reacting particles to collide with resulting in __more frequent collision__ and a __more frequent effective collision__ and a faster speed of reaction.

Concentration of Solutions

At a higher concentration, there are **more reacting particles per unit volume**. Thus the reacting particles are closer together resulting in __more frequent collisions__, __more frequent effective collision__ and a faster speed of reaction

Pressure of gases

At higher pressure, there are more reacting particles per unit volume, thus the reacting particles are closer together, resulting in more frequent collisions, more frequent reactions and a faster speed of reaction

Temperature of reactants

At a **higher temperature**, the **reacting particles will move faster and collide with more energy.** Thus there will be **more reacting particles** with **energy equal to or greater than the activation energy of the reaction** leading to more frequent effective collision and a faster speed of reaction

How does a catalyst work?

A catalyst provides **an alternative route** with a **lower activation energy** for the reaction to occur, thus **more reacting particles** having **energy equal or greater** than the catalysed activation energy result in **more frequent effective collision and a faster speed of reaction**