Chemistry 4.4 by Holly Jones https://padlet.com/hol_cjones/upvg1nqvqhib Made with whimsy en-us 2019-01-30 12:12:16 UTC 2024-12-18 19:28:25 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Soccerball.png Fehling's Solution hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795239 A red/orange precipitate forms when Fehling's solution is warmed with an aldehyde but not with a ketone.
Solution contains: Cu2+
Cu2+ + e- --> Cu+
Cu2O (red/orange ppt) is formed from Cu+ ions]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795239 Fehling's and Tollens' Test hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795240 Two reagents may be used for testing:
1) Tollens' reagent. containing the complex ion [Ag(NH3)2]+
2) Fehling's solution, containing Cu2+ ions]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795240 hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795241 Ketones resist oxidation. 
Aldehydes are easily oxidised.]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795241 Test for primary and secondary alcohols hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795242 Reagents: Potassium dichromate (VI) solution (K2Cr2O7(aq))
Dilute Sufuric acid (H2SO4(aq) )
Observations: Colour change from orange to green]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795242 Reduction hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795243 The removal of oxygen atoms or the addition of hydrogen atoms]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795243 Oxidation hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795244 The addition of oxygen atoms or the removal or hydrogen atoms]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795244 Oxidation of alcohol hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795245 Primary alcohol --> Aldehyde --> Carboxylic Acid
  • Extract the aldehyde using distillation 
  • Extract carboxylic acid using reflux 
Secondary alcohol --> Ketone
Needs H2SO4(aq) and K2Cr2O7(aq)
]]> 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795245 Aldehydes and Keytones hol_cjones https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795246 2019-01-30 12:12:28 UTC https://padlet.com/hol_cjones/upvg1nqvqhib/wish/325795246