We did an experiment with the synthesis of n-butyl bromide, using n-butyl alcohol, NaBr, and H2SO4. The question is: Aqueous sodium bicarbonate was used to wash the crude n-butyl bromide. A) What was the purpose of this wash? Give Equations. I know it was used to remove any remaining acid or n-butyl alcohol, but I don't know what it means by give equations? Please help. Also, B) Why would it be undesirable to wash the crude halide with aqueous sodium hydroxide? I think this has something to do with them possibly being able to react? Please Help.

Question

DrBob222 · Answer

The bicarbonate is used to wash the product because you want to remove the H2SO4 from the reaction.
H2SO4 + NaHCO3 ==> H2O + CO2 + Na2CO3 but you need to balance it.

Washing the alkyl halide with a strong base such as NaOH risks dehydrohalogenation (removal of HX---in this case HBr) to produce the alkene.

CMM · Answer

Thanks, but what happened to the S in the equation? There needs to be one in the products to balance.

Adelle · Answer

It is supposed to say, "Na2SO4" not "Na2CO3"