AnaChem Lab Finals

• In the 18th century, the strength concentration of vinegar sample was determined by noting the amount of ___ which had to be added, a little at a time, before bubbling ceased.

  Potassium carbonate K2CO3
• Active ingredients of vinegar

  Acetic Acid
• The greater the weight of potassium carbonate added to reach the point where the bubbling ended,


  the more concentrated the vinegar
• Occured during this process was due to the reaction with acetic acid, CH3CO2H.

  Effervescence
• the compound primarily responsible for the odor and taste of vinegar

  CH3CO2H acetic acid
• Acetic acid reacts with potassium carbonate

  
• The test of vinegar with potassium carbonate is one type of

  quantitative analysis
• The determination of the amount or concentration of a substance in a sample

  Quantitative analysis
• Non-instrumental methods of analysis

  Classical methods
• Classical methods of analytical chemistry are

  gravimetry and volumetry
• Using classical analytical methods, which are precise and accurate, you can determine the concentration of the analyte in the sample, but the analyte must be present

  in at least 0.1% of the sample
• Is the quantitative isolation of a substance by precipitation and weighing of the precipitate.

  Gravimetry or Gravimetric analysis
• General steps in gravimetric analysis

  
• Procedure of Gravimetric Analysis

  
• The signal is the mass of a precipitate

  Precipitation
• When we deposit the analyte as a solid film an electrode in an electrochemical cell. Ginagamit sa mga jewelries.

  Electrogravimetry
• When we use thermal or chemical energy to remove a volatile species. Oven or furnace ang ginagamit.

  Volatilization Gravimetry
• When we determine the analyte by separating it from the sample's matrix using a filtration or an extraction.

  Particulate gravimetry
• Sources of error in gravimetry

  
• Application for gravimetric methods

  
• Involves measurement of volumes of the reacting substances

  Volumetry or Volumetric Analysis
• Volumetric analysis is linked with the determination of


  equivalence point
• are chemicals that you add in your titration experiment that signifies the titration is done by color change

  indicators
• 2 types of solutions

  titrant and titrand
• solution of known concentration

  titrant
• sample or solution of uknown concentration

  titrand
• The weight of the required constituents is indirectly obtained by measuring the volume of a solution containing an unknown weight of the desired constituent.

  Volumetry or Volumetric Analysis
• titration between acid and base

  Neutralization reactions
• Titration in which insoluble precipitate is formed (argentometry)

  Precipitation reaction
• Reaction between metal ions and standard solution in which complex compounds are formed

  Complexometric reactions
• Reaction between oxidizing agent and reducing agent

  Oxidation-reduction (RedOx)
• Application of Volumetric Analysis

  
• Involve analytical measurements of some sample properties (conductivity, electrode potential, light absorption or emission, mass to chargebratio, fluorescence etc.

  Instrumental methods
• These measurements are made using instrumentation

  Instrumental Methods
• are commonly used because of much less sample used, lower analyte quantity that can be determined and results that can be produced more rapidly.

  Instrumental methods
• Advantages of Instrumental Methods of Analysis

  
• Advantages of Instrumental Methods of Analysis

  
• Limitations of instrumental methods of analysis

  
• Limitations of instrumental methods of analysis

  
• Many chemical reactions produce electric energy, a battery for example. The amount of chemical to produce a measured potential is calculated.

  Potentiometry