Definition: Natural occurrence of the process: Byproducts of the reaction: Conditions: Energy Requirement: Energy Released: Nuclear weapon: Source: Nuclear Fission vs Nuclear Fusion on Diffen Nuclear Fission Fission is the splitting of a large atom into two or more smaller ones. Fission reaction does not normally occur in nature. Fission produces many highly radioactive particles. Critical mass of the substance and high-speed neutrons are required. Takes little energy to split two atoms in a fission reaction. The energy released by fission is a million times greater than that released in chemical reactions, but lower than the energy released by nuclear fusion. One class of nuclear weapon isa fission bomb, also known as an atomic bomb or atom bomb. Nuclear Fusion Fusion is the fusing of two or more lighter atoms into a larger one. Fusion oceurs in stars, such as the sun. Few radioactive particles are produced by fusion reaction, but if a fission "trigger" is used, radioactive particles will tesult from that. High density, high temperature environment is required. Extremely high energy is required to bring two or more protons close enough that nuclear forees overcome their electrostatic repulsion. The energy released by fusion is three to four times greater than the energy released by fission. One class of nuclear weapon is the hydrogen bomb, which uses a fission reaction to “trigger” a fusion reaction. Powered by DiffenThese effects are a combination of RESONANCE and INDUCTIVE effects The effects are also important in other reactions and properties (e.g. acidity of the substituted benzoic acids). Here are some general pointers for recognising the substituent effects: The H atom is the standard and is regarded as having no effect. Activating groups increase the rate Deactivating groups decrease the rate = EDG = electron donating group EDG can be recognised by lone pairs on the atom adjacent to the m system, eg: - OCH except -R, -Ar or -vinyl (hyperconjugation, Tt electrons) EWG = electron withdrawing group EWG can be recognised either by the atom adjacent to the 1 system having several bonds to more electronegative atoms, or, having a formal +ve or 6 +ve charge, eg: - COR, -NO2 EDG / activating groups direct ortho / para EWG / deactivating groups direct meta except halogens (-X) which are deactivating BUT direct ortho / para EDG add electron density to the m system making it more nucleophilic EWG remove electron density from the m system making it less nucleophilic.These effects are a combination of RESONANCE and INDUCTIVE effects The effects are also important in other reactions and properties (e.g. acidity of the substituted benzoic acids). Here are some general pointers for recognising the substituent effects: The H atom is the standard and is regarded as having no effect. Activating groups increase the rate Deactivating groups decrease the rate = EDG = electron donating group EDG can be recognised by lone pairs on the atom adjacent to the m system, eg: - OCH except -R, -Ar or -vinyl (hyperconjugation, Tt electrons) EWG = electron withdrawing group EWG can be recognised either by the atom adjacent to the 1 system having several bonds to more electronegative atoms, or, having a formal +ve or 6 +ve charge, eg: - COR, -NO2 EDG / activating groups direct ortho / para EWG / deactivating groups direct meta except halogens (-X) which are deactivating BUT direct ortho / para EDG add electron density to the m system making it more nucleophilic EWG remove electron density from the m system making it less nucleophilic.Reference J ‘Weakly Deactivating Moderately DeactivatingCommon Polyatomic lons Formula Name Charge = 1— H,PO, | Dihydrogen phosphate | C,H,0,- | HSO,- /HCO, | Hydrogen carbonate | Nitrite Nitrate 2 Permanganate s Hypochlorite = Chlorite Chlorate = Perchlorate Charge = 2— HPQ,?- | Hydrogen phosphate C,0,- | Oxalate S Sulfite Sulfate Carbonate Chromate ichromate ate Charge = 3— Phosphite Phosphate Charge = 1+ NH." _ AmmoniumThe Main Types of Chemical Reactions A chemical reaction may be regarded as the process that occurs when matter undergoes change in composition. To be able to understand chemical reactions, ‘one needs to recognize the key types of reactions. Reactions may be classified in several different ways, namely: ‘Synthesis (Combination) Reactions; Decomposition Reactions; Substitution (single replacement) Reactions; Precipitation (Double replacement) Reactions; Neutra lisation (acid-base) Reactions; Redox (Reduction and Oxidation) Reactions. of Reaction slanation General Equation Example igs = Bel |General tor of change occuererees) i Synthon Reeshaineldi ewer, || aee=ae 284,40; -3H,0 Cartiaton | more drpler abetonens Glonsead combina Shemlaly o gve ‘compound. Decompoiicion | Reaction in witcha eerers 2H,0=2H, +0, Soaps besten pesgeeyans ‘ubicances (elements) Substitution Reacominwisnan | avac-aces | zneaHcl~zncie My GGingie om or geupotaroms | OR ee ea | Peeehen” | Aseccease | Cheaninr—alaciany, som or group Precipitation | Reactioninwhich acotd | ARSD—AD+EB | AgNO,+ NaCl ~ Age! + NaNO, (ouble Compound is ormed replacement) | whem solution of wo Joluble compounds arembeed. Newraiation | Reactloninwhich an acid | HA* BON ~H,0+0A | HEI+nacH 10% Mac (Acid: Base) ences wth a base ce give keno wane Redox Reaction in which Reduerton: A: SC, Ae: 20k (gain aleetrocis) (Redaction ‘dectren ander occurs. | Onidaton:® Na Se Goi of ecto) nidation) 44The Zeroth Law ! If Object 1 is in thermal equilibrium with Object 2 and Object 2 is in thermal equilibrium with Object 3, then Object 1 is in thermal equilibrium with Object 3. S&S Thermodynamic Equilibrium ,2:"., (Zeroth Law) Center Object #1 Well, duh (Thermometer) When two objects are separately in thermodynamic equilibrium with a third object, they are in equilibrium with each other. Objects in thermodynamic equilibrium have the same temperature.Tiwe [Bespin [hnee? —_[Eamoie Alpha Nucleus releases a He atom. He atom is known as an alpha particle Nucleus releases an electron and converts a neutron to a proton Nucleus goes from high energy state to a low energy state, Positron Nucleus releases a positively charged electron and converts a proton to a neutron An electron from the electron cloud converts @ proton into a neutron Electron Capture A Helium atom is released. Remaining nucleus weighs 4 less and has 2 less protons Remaining atom has: “Same mass *One more proton, one less neutron Nucleus remains same, but a gamma ray is released Remaining atom has: “Same mass *One more neutron, one less proton Remaining atom has: “Same mass *One more neutron, one less protonCatalyst lowers the activation energy for both forward and reverse reactions.AQUEOUS SODIUM HYDROXIDE os see — $cc - ©: POTASSIUM CYANIDE Ge= ‘< a =Stephen ‘quantity of non-PV work that a system can perform in terms of | enthalpy and Boo: | — under conditions oF constant TandP (Gibbs free energy) I known as the constant Tamd V (Helmholtz) free energy) for a chemical reaction system is based on J diferencae in also expresses standard free energies the of formation of products and reactants T is revealed by “escaping tendency” v in wien oF a reaction component T plots showing Delta-H in terms of and 7-Delta S ee J as functions of T <0 . =0-means l showing that the reaction Is in equilitrium. Temperature dependence (Delta-G = 0) when — proceeds to the right T = Delta-H/Delta-S reaction proceeds to the leftLow melting and boiling points Softer and squishier a fe More flammable Not soluble in water | lige Doesn't conduct electricity in water High melting and boiling points Less flammable ‘Soluble in water 4 Conducts electricity in waterINITIATION ee — 6: @ Free radicals formed PROPAGATION + @ — ++ GO Free radicals used and re-generated ch Ge — che -6 TERMINATION @ + ©& — €@e TERMINATION of 0 —ofe Two methyl radicals combine to form ethane° ° ° Charges, Names, and Formulas of Common Ions Positive lons (Cations) Negative lons (Anions) +1 Charge -1 Charge Name Formula Name Formula Ammonium NH,* Acetate C,H,O0,- Copper() Cut Bromide Br Lithium Lit Chloride cr Potassium Kt Dihydrogen H,PO,” Silver Ag* Phosphate Sodium Na* Fluoride FE Hydroxide OH™ +2 Charge Hydrogen HCO,- Name Formula Carbonate (bicarbonate) Barium Ba** Hydrogen HSO,- Calcium Ca** Sulfate (bisuitate) Copper(Il) Cu?* Hypochlorite clo- lroni(|l) Fe?* lodide F Lead(I!) Pb?t Nitrate NO, Magnesium Mg?* Permanganate Mno,> Nickel Niz* Thiocyanate SCN- Strontium srt Tin() sre a charus Zinc Zn?* Name_________— Formula. Carbonate co, +3 Charge Chromate CrO,- Name Formula _ Dichromate Cr,0,;7- Aluminun OA Hygeoam ‘ HPO,* 3+ josphate lron({ll) Fe Oxide o +4 Charge Oxalate C,0,7 Name Formula Sulfate SO. Lead) Pb* Sulfite sO. Tin(IV) Sn** ~3 Charge LI Name Formula Nitride Ne mm cuenTicic ne Phosphate Po?" ‘aPse