1 / 21

Jonah Chevrier Nick Jiang Ushhud Khalid Philip Van-Lane

Gravimetric Estimation of Chloride Ions. Jonah Chevrier Nick Jiang Ushhud Khalid Philip Van-Lane. Introduction. Gravimetric Analysis is used to determine the amount of a substance Stoichiometry is the study of the relationships between products and reactants

clyde
Download Presentation

Jonah Chevrier Nick Jiang Ushhud Khalid Philip Van-Lane

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Gravimetric Estimation of Chloride Ions Jonah Chevrier Nick Jiang Ushhud Khalid Philip Van-Lane

  2. Introduction • Gravimetric Analysis isused to determine the amount of a substance • Stoichiometry is the study of the relationships between products and reactants • Gravimetric stoichiometryis the combination of gravimetric analysis and stoichiometry

  3. Objective • Approximate the amount of Cl- ions in AgCl AgNO3 (aq) + NaCl(aq) AgCl(s) + NaNO3(aq) • Dealing with limiting and excess reagents • Filter out the AgCl from the NaNO3

  4. Materials • Safety Goggles • Distilled Water • NaCl (0.117g) and AgNO3(aq) • Beaker • Erlenmeyer Flask • Dropper • Funnel • 1 piece of (Whatman) filter paper • Porcelain crucible and lid • Crucible tongs • Ring clamp • Retort stand • Clay triangle • Bunsen burner • Accurate scale

  5. Procedure 1. Measured mass of empty crucible 2. NaClsolution created 3. Small amounts of AgNO3 added 4. AgCl filtered using filter paper and funnel

  6. Procedure Part 2 5. After the filter paper had dried, it was carefully placed in the crucible 6. Filter was allowed to burn; AgCl remained in the crucible 7. Found mass of AgCl

  7. Safety Precautions • Safety goggles were worn at all times • Workspace was free of clutter • All hot materials were handled with care • All substances were handled properly

  8. Observations – Qualitative • NaCl and AgNO3 were clear, aqueous solutions • Precipitate of AgCl formed from a double displacement reaction • Black substances remain; carbon from filter paper which had not totally dissipated

  9. Observations – Qualitative

  10. Observations – Quantitative

  11. Calculations n = Number of molecules NA • n = _ Mass _ • Molar Mass Theoretical: 0.002 moles Actual: 0.002226475 moles Theoretical: 1.2044 * 1021 molecules Actual: 1.3407843432 * 1021 molecules

  12. Calculations Part 2 Percentage Yield | Actual / Theoretical | *100 =111.32% Percentage of Error | (Theoretical – Actual) / Theoretical | *100 =11.32%

  13. Discussion • Initial problem was to separate AgCl(s) from the NaNO3(aq) • Both have very high boiling points; evaporation would not be feasible • Gravimetric analysis was used for convenience

  14. Discussion Part 2: Analytical Chemistry • Study of chemical composition of natural and artificial materials • Deals with 3 main questions • What chemicals are present? • Characteristics of the chemicals? • Quantity of the chemicals? • Quantitative • Amount of chemicals • Qualititative • Determining presence of chemicals

  15. Analytical Chemistry Part 2 • Much focus on it between the 17th and 20th centuries • First kind of instrumental analysis flame emissive spectrometry • Robert Bunsen, 1860 • Most studied branch of chemistry

  16. Discussion Part 3: Thermogravimetric Analysis • Part of instrumental analysis branch • Study of weight changes in relation to temperature • Used to determine characteristics of polymers • Large molecules composed of repeating structural units

  17. Discussion Part 4: Volumetric Titration • Another traditional analytical technique • Reagent of known concentration and volume • Titrant • Solution of unknown volume and concentration • Titrand

  18. Volumetric Titration Part 2 • Volume, instead of mass, is measured • Titrant is added to titrand until endpoint is reached • Indicators make endpoint obvious to observers • Most often used for neutralization reactions • Acid + Base  Water + Ionic Salt

  19. Conclusion • Precipitate of AgCl formed through double displacement reaction AgNO3 (aq) + NaCl(aq) AgCl(s)+ NaNO3(aq) • 0.3191g of AgCl • 1.3407843432 * 1021Cl- ions in precipitate • Carbon particles remained • Added to mass

  20. Sources of Error • Inconsistence balance readings • Contamination of chemical substances • Uncertain if the Cl- ions had completely reacted with the Ag+ ions • Qualitative filter paper did not disintegrate • Residue left in crucible from previous experiments

  21. Suggested Modifications • Use of quantitative filter paper rather than qualitative • More accurate balances • Using materials which may not have been contaminated from previous experiments

More Related