Answer:
1-bromobutane, unlike others, will not be removed because it is an <em>alkane</em> and inert to concentrated sulfuric acid.
Explanation:
<em>Alkanes</em> are saturated organic compounds, primarily made up of hydrogen and carbon atoms. Saturation implies that they posses no double or triple bonds, therefore making them stable and unresponsive to addition reactions and also, concentrated sulfuric acid.
1-Butanol is a primary alcohol. Primary alcohols will react with acids to produce alkyl halides. 1-butene, as an alkene, will react with concentrated sulfuric acid to produce alkyl hyrgensulfate, while di-n-butyl will produce an ether when it reacts with concentrated sulfuric acid.
Therefore, these organic compounds will be washed and converted to other compounds by concentrated sulfuric acid except 1-bromobutane.