Which one of the following statements about dihydrogen (H₂) is not cor

Which one of the following statements about dihydrogen (H₂) is not correct ?

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H₂ is lighter than air and insoluble in water.

H₂ is inert at room temperature due to high H – H bond dissociation enthalpy.

H₂ reacts with alkali metals at high temperature to yield metal hydrides.

A mixture of NO₂ and H₂ is known as Syngas.

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2021

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The statement “A mixture of NO₂ and H₂ is known as Syngas” is not correct. Syngas (synthesis gas) is primarily a mixture of carbon monoxide (CO) and hydrogen (H₂).

Syngas is a fuel gas mixture that can be produced from various carbon-containing materials like natural gas, coal, biomass, or plastic waste. It is used as a fuel or as an intermediate for the production of other chemicals like methanol and ammonia. Nitrogen dioxide (NO₂) is a toxic gas primarily associated with air pollution.

Dihydrogen (H₂) is indeed lighter than air and practically insoluble in water. Its high H–H bond dissociation enthalpy (435 kJ/mol) makes it quite stable and inert at room temperature. At high temperatures, it reacts with alkali metals (like Na, K, Li) to form ionic hydrides (e.g., 2Na + H₂ → 2NaH), where hydrogen acts as an anion (H⁻).

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