Hydrolysis of t-butyl halides

The color of the solution with indicator changes from blue to yellow after different time intervals

Scientific name: Alkaline hydrolysis of haloalkanes leads to a change in the reaction medium from an alkaline to acid due to the formation of HBr

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Hydrolysis of t-butyl halides

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hydrolysis of t-butyl chloride

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www.chem2all.blogspot.com

by chemistvip

Hydrolysis of t-Butyl Chloride

by wickee007

www.chem2all.blogspot.com

by chemistvip

Sn1 reaction tert butyl chloride with hydroxide in acetone and water

by Scott Milam

Hydrolysis of t-ButylChloride. Kinetics. Experiment #5. SN1 Reaction.

by uofgchem2700

Safety

Wear eye protection goggles. Use gloves.

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Reaction formula

(CH3)3CBr + H2O → (CH3)3COH + HBr

(CH3)3CCl + H2O → (CH3)3COH + HCl

NaOH + HBr → NaBr + H2O

Step-by-step instruction

  1. Prepare the solvent. Mix 200 ml of water and 30 mL of acetone in a 300-ml beaker.
  2. Add 7.5 ml of 1M sodium hydroxide solution and a small amount of bromothymol blue.
  3. Increase the volume of the resulting solution to 300 ml with water and mix.
  4. Divide the solution into 2 portions of 150 ml, pour each into a glass jar.
  5. Prepare solutions of tert-butyl halides. Dissolve 920 mg of t-butyl chloride in 10 ml of acetone. Dissolve 1370 mg of t-butyl bromide in 10 ml of acetone.
  6. Transfer the solution of tert-butyl chloride into the first jar and the solution of t-butyl bromide into the second jar.
  7. Close the jars and shake them.
  8. After some time there will be a color change from blue to yellow in the jar with t-butyl bromide. Much later, it will happen in the jar with a tert-butyl chloride.

Scientific background

Tert-butyl halide is suspect to alkaline hydrolysis like all haloalkanes.

Hydrolysis of the t-butyl halide proceeds via a mechanism forming a carbocation (SN1).

R-X --> R+ → R-OH

The reaction rate doesn't depend on the concentration of the nucleophile, but depends on the nature of the substrate. Bromine is a better leaving group than chloro, so the reaction with t-butyl bromide proceeds much faster. The color change of the indicator is due to changes in the reaction medium from alkaline to acid due to the formation of hydrogen bromide.

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Published on 15 May 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst