1 / 17

Redox Titration OF bleach

Due Today: 1. Redox Titration of Bleach Pre-Lab 2. Copper Reduction Formal Lab Report Homework: 1. Redox Titration Short Report 2. Gravimetric Analysis of Phosphorus Pre-Lab. Redox Titration OF bleach . Objective.

mala
Download Presentation

Redox Titration OF bleach

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. Due Today: 1. Redox Titration of Bleach Pre-Lab 2. Copper Reduction Formal Lab Report Homework: 1. Redox Titration Short Report 2. Gravimetric Analysis of Phosphorus Pre-Lab Redox Titration OF bleach

  2. Objective • Determine the weight percent of sodium hypochlorite (NaOCl) in bleach via redox titration.

  3. Key Terms • Oxidation-Reduction (Redox) Reaction: • Follow the transfer of electrons • Matched reaction – you cannot have one without the other

  4. Key Terms • Titration – process of reacting a solution of unknown concentration with a solution of a known concentration until the reaction is JUST complete • All reactants are limiting

  5. Key Terms • Equivalence Point – equal quantities of opposite solutions exist • For acid/base titrations: Moles of acid = Moles of base • For redox titrations, you must you the reaction equation to determine moles

  6. Procedure Notes • Preparation of KIO3 Solution: • Use 250 mL volumetric flask • Be precise!

  7. Procedure Notes • Standardization of (Na2S2O3): • Rinse the buret with DI water and Na2S2O3 before you titrate • PIPETE KIO3 solution • DO NOT PIPET FROM VOLUMETRIC FLASK!! • IMMEDIATELY titrate after KI is added

  8. Procedure Notes • During the Titration: • Look for light yellow color • Add starch • Blue/Black • Titrate until clear • 1-5 drops • 3 good trials • Molarities within 5% of average

  9. Procedure Notes • Titration of Bleach • Weigh 2.000g of bleach • During the Titration: • Immediately titrate when you add KI • Look for light yellow color

  10. Procedure Notes • Add starch • Blue/Black • Titrate until clear • 1-5 drops • 3 good trials • Molarities within 5% of average • RECORD THE REPORTED MASS NaOCl FROM THE BLEACH BOTTLE!!!!!!!

  11. Waste • Solutions can go down the drain

  12. Risk assessment • Sodium Hypochlorite (Bleach) • Danger • Skin Irritant • Respiratory Irritant

  13. calculations • Molarity of KIO3 Solution: • Moles KIO3 used in titration:

  14. calculations • Moles of Na2S2O3 used in titration: • You will need to use stoichiometry • HINT look for a relationship between the two equations on page 44 • Mass Percent:

  15. Redox Equation Example Redox Equation: 1. Make sure your equation is balanced

  16. Redox equation example 2. Assign Oxidation Numbers Cu: 0 Cu : +2 S : +4 O : -8 Zn: 0 Zn : +2 S : +4 O : -8

  17. Redox equation example 3. Determine which species is oxidized and reduced Cu : +2 S : +4 O : -8 Zn: 0 Zn : +2 S : +4 O : -8 Cu: 0 Zn: 0→+2 loss of electrons Zinc is oxidized and is the reducing agent Cu: +2→0 gain electrons Copper is reduced and is the oxidizing agent

More Related