Notes For Chemistry

[Archimedes]

Hey guys every once in a while i'm going to be writing up notes for Chemistry Unit 4. These are useful for exam prep and believe that are useful in extracted from heavy textbooks the key components to focus on. Please feel free to comment and add anything useful, all are welome. Please rate also. 

[Archimedes]

Industrial Chemistry      
Rate of reaction:
1.   Chemical reactions involve the rearrangement of atoms. Some chemical reactions are fast, while some are slow. The ignition of rocket fuel is a very fast reaction, while the rusting of iron metal is a slow reaction.
2.   The rate of a chemical reaction is the speed with which reactants are converted to products. Experimentally, reaction rates depend on:
•   Temperature
•   The concentration of the reactants
•   The surface area of a solid
•   The pressure for gases
•   The presence of a catalyst
3.   Reaction rate also decreases as the reaction proceeds since the reactants are used up.
4.   The collision theory helps explain why chemical reactions occur at different rates. The theory states that for a chemical reaction to occur, the reaction particles (either atoms, ions or molecules) must collide. The more collisions per unit time, the faster the reaction.
5.   For a reaction to occur the reactant particles must:
•   Collide with sufficient energy to break any bonds
•   Have suitable orientation for breaking bonds
6.   The activation energy is the minimum energy that colliding particles must have for collisions to form products. No reaction occurs if particles collide with insufficient energy to break the chemical bonds.
7.   According to the collision theory:
•   Increasing the concentration of a reactant increases the number of particles available for collision and increases the number of successful collisions;
•   Increasing the pressure of gas increases the concentration of the gas molecules, and this increases the reaction rate;
•   Increasing temperature increases the kinetic energy of the particles, and so there is more energy available to break any bonds and the number of collisions per second also increases;
•   A solid will react faster if it is ground into a powder, since its surface area is increased and this increases the likelihood of collisions with the other reactants.
8.   Catalysts speed up reactions without being consumed. A catalyst allows a reaction to occur in such a way that less energy is required (they lower the activation energy), thus more collisions will be successful and the reaction proceeds faster.

[liuetenant]

yeee, thanks for your dedication!

[bawse]

Great work Archimedes!

[taiga]

Looks useful (Y) but are you creating accounts to give yourself more respect? :S

[ninwa]

Looks useful (Y) but are you creating accounts to give yourself more respect? :S

yeah that's really lame, can you not do that please