Chemistry- F332

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A Levels Chemistry Mind Map on Chemistry- F332, created by els17 on 05/26/2014.
els17
Mind Map by els17, updated more than 1 year ago
els17
Created by els17 over 10 years ago
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Resource summary

Chemistry- F332
  1. Continuous process- (doughnut)
    1. Example: production of chlorine using a membrane cell
      1. Reactants are entering the reaction vessel, the reaction is taking place and the products are being removed continuously.
      2. Advantages: More produce can be made, more economic-running costs lower due to lower energy requirements, less environmental pollution, more time efficient, less labour (automatic machines)
        1. Disadvantages: very wasteful if it goes wrong, only one product, high start up cost
        2. Batch- (cake)
          1. Stages occur at separate times in sequence. After the reaction is over the vessel is emptied and the process starts again
            1. Advantages: not very wasteful if goes wrong, low start up cost
              1. Disadvantages: less produce, more time consuming
              2. Mercury Cell- large scale method for making chlorine
                1. gradually being phased out, losses of toxic mercury to the environment, more expensive to run
                2. chemical manufacture- batch or continuous
                  1. most chemical processes involve- feedstock preparation -->reaction-->separation--> products
                    1. Feedstock= reactants needed for the chemical process, prepared from raw materials present in the environment (eg. natural gas, crude oil, coal, limestone, air, water)
                      1. Handling of feedstock is important
                        1. gases and liquids can be piped, but solids are expensive to handle
                      2. Co-products= products other than the desired on formed in the reaction.
                        1. By-products= produced as a result of unwanted side reactions. do not appear in reaction equation. conditions can be altered to minimise these reactions.
                          1. the separation stage- produces the pure product, un-reacted feedstock, any co-products, bi- products
                            1. un-reacted feedstock is recycled to reactor and increases the efficient of the process. also minimises waste effluent
                          2. Cost- research and development, plant design, construction and start up.
                            1. Fixed costs, have to be paid no matter how much product made. eg. cost of construction (capital cost)
                              1. Variable costs- depend on level of production. greater production- greater variable costs eg. raw material, effluent treatment and distribution
                              2. Efficiency
                                1. energy is expensive- therefore needs to be efficient
                                  1. exothermic reaction give out heat which by using heat exchanger can produce hot water/ steam which can be used
                                    1. When choosing temperature and pressure- some may go for highest value--> but this is costly to build and maintain. yield could be affected
                              3. Transporting dangerous liquids
                                1. Safety procedures: protective clothing+ breathing apparatus, concrete base- stops soil from absorbing, lead-lined steel for lorry (unreactive-strong incase of collision/impact), glass-lined steel ( unreactive), pressurised nitrogen tank, bromine detector, dump tank
                                2. Electronic configuration
                                  1. Rules for filling shells: 1) fill lowest energy orbitals first (bottom upwards) 2) a maximum of 2 electrons can occupy any orbital 3) if there are equal energy orbitals, electrons occupy them singularly before pairing
                                    1. Hund's Rule: there is a special stability associated with a half-filled or filled set of orbitals
                                    2. Ionisation energy
                                      1. When 1 mole of a gaseous element turns into a mole of gaseous ions, freeing 1 mole of electrons
                                        1. First ionisation energy: X(g) --> X^+ (g) + e^-
                                          1. Second ionisation energy: X^+(g) --> x^2+(g) + e^-
                                            1. Third ionisation energy: X^2+(g) --> x^3+(g) + e^-
                                          2. Ionisation energy increases successively (one follows the other) because we are removing electrons from an increasingly positive ion.
                                            1. For Na, the 2nd I.E means taking energy from a full inner shell- more nuclear attraction as it is closer to the nucleus
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