Review exercises 2 ESO

• Balance these chemical equations:

1. Co + O2 => Co2O3
2. C4H8 + O2 =>  CO2 +  H2O
3. Fe + HCl =>  FeCl2 +  H2
4. Na + H2O => Na2O + H2

• Determine wheter these are chemical or physical:

1. Melting of ice
2. Oxidation of a wet screw
3. Solving salt into water
4. Drilling a wall
5. Photosynthesis

• Imagine this reaction of a fuel: CnH2n + O2 => CO2 + H2O. Tell if these factors will affect the reaction rate

1. The fuel is cooled to solid state
2. The fuel is vaporised
3. We control the temoperature reaction to 30ºC. 
4. We let the reaction temperature reach 1500ºC

• Tell if these proccess is biological or industrial:

1. Synthesis of a polymer
2. Human breathing
3. Mythosis
4. Cracking of oil

• Are these statements true or false. Tell why

1. The combustion of fuels affects the ozone layer.
2. CFCs provoque the ozone-s layer depletion
3. Global warming is only provoqued by the industrial activity
4. Atmospheric polution only provoques global warming
5. Soil polution has to do with waste dumping.
6. Only industries pollute water