ANACHEM CHAP5&6

• titration 


  it is a volumetric analysis in which substances react to completion, often observed using chemical indicators.
• Neutralization titration 


  are widely used to determine the amount of acids and bases.
• Neutralization titration 


  it can be used to monitor the progress of reactions that produce or consume hydrogen ions.
• titrant 


  it is added to analyte until their reaction is complete. it is usually delivered from a burette.
• In a titration, increments or reagent solution, the titrant are added to analyte until their reaction is complete. From the quantity of titrant required, we can calculate the quantity of analyte that must have been present. Titrant is usually delivered from a burette.
• Analyte 


  the substance without known concentration or identity
• titrant/ standard


  the substance without accurately known concentration
• indicators


  substance that produce distinct color at certain pH
• equivalence point


  the point at which the reaction is complete, usually computed using stoichiometry
• end point 


  an estimate position at which an equivalence point condition is observed, usually done in experiment
• Henderson-Hasselbalch equation


  Use the _ if a presence of acid-conjugate base or base-conjugate acid pairs
• if there is a presence of acid-conjugate base or base-conjugate acid pairs, use the Henderson-Hasselbalch equation
• upon the addition of acid, the moles of base decreases
• upon the addition of base, the moles of acid decreases
• Addition of two liquids (titrant and analyte) will change the concentrations of the species in aqueous media. Always use the dilution equation.
• monoprotic titrations refer to titrations whose ration of analyte and titrant is 1:1
• Strong acid- strong base titration is ruled by basic stoichiometry and dilution calculations
• Weak acid- strong base titration is ruled by equilibrium equations
• Weak base- strong acid titration is ruled by equilibrium equations
• Monoprotic SA-SB refers to titrations whose strong acids are analytes and strong bases are titrants. It is composed of 4 stages.
• Monoprotic SB-SA refers to titration whose strong bases are analytes and strong acids are titrants.
• Monoprotic WA-SB titration refers to titrations whose weak acids are analytes and strong bases are titrants.
• A buffered solution resist changes in pH when acids or bases are added or when dilution occurs. The buffer is a mixture of an acid and its conjugate base. There must be comparable amounts of the conjugate acid and base to exert significant buffering.
• Titrators are mostly organic acids and bases which changes color depending on the pH of the solution. It must be added in minimal amounts (3 to 5 drops) to minimize the effect in the end point.
• Electrochemistry is the branch of chemistry that deal with the interconversion of electrical energy and chemical energy.
• Electrochemical processes are redox reaction in which the energy released by spontaneous reaction is converted to electricity, or in which electrical energy is used to cause a nonspontaneous reaction to occur.
• Oxidation number is the charge of an atom (free state or in a molecule) if electrons around it were completely transferred, rather than shared.
• Oxidation is the loss of electron(s)
• Reduction is the gain of electron(s).
• oxidation- reduction reaction (redox) are where electrons are transferred from one species to another. In redox, reactions, two separate reaction occur simultaneously.
• Reduction reactions are reactions where electrons are gained by the species.
• Oxidation reactions are reactions where electrons are given off by the species.
• An electrochemical cell is a system consisting of electrodes that dip into an electrolyte and in which a chemical reaction either uses or generate an electric current.
• A voltaic, or galvanic, cell is an electrochemical cell in which a spontaneous reaction generates an electric current.
• An electrolytic cell is an electrochemical cell in which an electric current drives an otherwise nonspontaneous reaction.
• The electrode at which oxidation occurs is called the anode.
• The other electrode at which the reduction occurs is called the cathode.
• A salt bridge is a tube on an electrolyte in a gel that is connected to the two half-cells of a voltaic cell; the salt bridge allows the flow of ions but prevents the mixing of the different solutions that would allow direct reaction of the cell reactants.
• By convention, oxidation reactions are on the anode (left) and reduction reactions are on the cathode (right).
• A cell potential is a measure of the driving force of the cell reaction. This reaction occurs in the cell as separate half-reactions: and oxidation half-reaction and a reduction half-raction \