Which of the alkyl halides on conversion into the Grignard reagent followed by treatment with water, will yield n-pentane?

All of these

The correct answer is option 4. All of these.

All of the alkyl halides listed will yield n-pentane when they are converted into the Grignard reagent and then treated with water.

The Grignard reagent is a type of organometallic compound that is formed when an alkyl halide reacts with magnesium metal in an anhydrous ether solvent. The Grignard reagent is a strong nucleophile and will react with water to form an alkane.

The alkane that is formed will have the same number of carbon atoms as the alkyl halide that was used to make the Grignard reagent. In this case, all of the alkyl halides listed have five carbon atoms, so the alkane that is formed will also have five carbon atoms.

Therefore, all of the alkyl halides listed will yield n-pentane when they are converted into the Grignard reagent and then treated with water.