Which compound will give propane when it Is dehy drated by an excess of hot, concentrated tetraoxosvlphate(VI) acid?

Analyze the question: Dehydration with excess hot concentrated H₂SO₄ removes water from an alcohol to form an alkene. The question says "propane", but propane (C₃H₈) is an alkane and cannot form by dehydration. The intended product is almost certainly propene (C₃H₆), and "propane" is a typo or a misprint in the question.

Concept: Excess concentrated H₂SO₄ at about 170 °C dehydrates an alcohol by removing –OH and an H from the adjacent carbon, giving an alkene:

CH₃CH₂CH₂OH → (conc. H₂SO₄, 170 °C) → CH₃CH=CH₂ + H₂O

Checking the options:

• A. CH₃CH₂CHO is propanal, an aldehyde. It has no –OH to lose, so it is not dehydrated this way.
• B. CH₃CH₂CH₂OH is propan-1-ol, a 3-carbon alcohol. It gives propene on dehydration. ✔
• C. CH₃CH₂COOH is propanoic acid, a carboxylic acid. It does not give an alkene this way.
• D. The formula is garbled. It was probably an ether or ester, such as CH₃CH₂OCH₃, which does not give a 3-carbon alkene cleanly.
• E. CH₃CH₂OH is ethanol, which has 2 carbons. It gives ethene, not a 3-carbon product.

Answer: Option B is the only 3-carbon alcohol, so it is the only one that gives the three-carbon alkene (propene).

Tip: With excess hot conc. H₂SO₄, think "alcohol → alkene". With excess alcohol at about 140 °C, you get an ether instead. Also watch the wording: dehydration never gives an alkane, so when you see "propane" in a question like this, read it as "propene".