If n-butyl alcohol, sodium bromide, water, and concentrated sulfuric acid (cooled in ice bath while adding H2SO4) are placed in a flask and refluxed, what are the formulas of the salts that precipitate when the reaction mixture is cooled?

To determine the formulas of the salts that precipitate when the reaction mixture is cooled, we need to understand the reaction taking place.

In this case, when n-butyl alcohol, sodium bromide, water, and concentrated sulfuric acid are refluxed, a substitution reaction known as an S N 2 reaction occurs. The bromide ion (Br-) from sodium bromide gets substituted with the butyl group (-C4H9) from n-butyl alcohol.

The reaction can be represented as follows:

C4H9OH (n-butyl alcohol) + NaBr (sodium bromide) → C4H9Br (n-butyl bromide) + NaOH (sodium hydroxide)

When the reaction mixture is cooled, the n-butyl bromide product is less soluble in the cooled solution and thus precipitates out as a solid. The sodium hydroxide formed as a byproduct will remain dissolved in the solution.

The chemical formula of n-butyl bromide is C4H9Br, and the formula of sodium hydroxide is NaOH. These are the salts that precipitate when the reaction mixture is cooled.

To summarize, the reaction described results in the formation of n-butyl bromide (C4H9Br) as a precipitate and sodium hydroxide (NaOH) remaining in the solution.

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