📘 Chapter: Hydrogen – Complete Notes

Here's a well-structured Notes of Chapter Hydrogen, ideal for NEB or entrance preparation CEE. This Note is informative and written in a student-friendly tone while maintaining scientific accuracy.

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📘 Chapter: Hydrogen – Complete Notes | Inorganic Chemistry | #mission_cee

Welcome back dear learners! 😊❤️

Today, we bring you complete and well-explained notes of “Hydrogen”, one of the most important chapters in Inorganic Chemistry. Whether you are preparing for NEB Grade 11/12, CEE (Medical/Engineering), or other entrance exams, this chapter holds great weight. Let's dive into it!

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🌟 Introduction to Hydrogen

Symbol: H

Atomic Number: 1

Electronic Configuration: 1s¹

Position in Periodic Table: Group 1 (like alkali metals) and also resembles halogens due to its ability to gain one electron.

🔹 Hydrogen is the lightest and first element in the periodic table.

🔹 It forms about 75% of the mass of the universe.

🔹 It exists in diatomic molecular form (H₂).

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🔍 Isotopes of Hydrogen

Hydrogen has three isotopes: | Isotope | Symbol | Proton | Neutron | Electron | % Abundance | Other Name | |--------|--------|--------|---------|----------|--------------|------------| | Protium | ¹H | 1 | 0 | 1 | 99.98% | Normal hydrogen | | Deuterium | ²H or D | 1 | 1 | 1 | 0.02% | Heavy hydrogen | | Tritium | ³H or T | 1 | 2 | 1 | Traces | Radioactive |

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⚗️ Physical Properties

Colorless, odorless, tasteless gas.

Lightest gas known.

Insoluble in water.

Highly combustible.

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⚗️ Chemical Properties

1. Reaction with Non-metals:

With O₂ → Forms Water (H₂O)

With Cl₂ → Forms Hydrogen chloride (HCl)

With N₂ → Forms Ammonia (NH₃) (in Haber’s process)

2. Reaction with Metals:

Forms metal hydrides (e.g., NaH, CaH₂)

3. Combustion:

H₂ + O₂ → H₂O + Energy (Explosive in air!)

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🧪 Types of Hydrogen

1. Atomic Hydrogen (H•) – Very reactive, used in welding.

2. Nascent Hydrogen – Freshly prepared hydrogen, more reactive than molecular H₂.

3. Ortho and Para Hydrogen – Based on spin of nuclei in H₂ molecules.

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🔄 Hydrogen as a Reducing Agent

Hydrogen can reduce many metal oxides to metal: E.g.

CuO + H₂ → Cu + H₂O

Fe₂O₃ + 3H₂ → 2Fe + 3H₂O

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🏭 Industrial Preparation of Hydrogen

1. From water gas (CO + H₂)

2. Electrolysis of water

3. Steam reforming of hydrocarbons

4. Reaction of metals with acids (Lab method):

Zn + 2HCl → ZnCl₂ + H₂↑

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🌱 Uses of Hydrogen

Fuel (Clean and eco-friendly)

Ammonia production (Haber’s process)

Hydrogenation of oils

Rocket fuel

Welding (Atomic hydrogen torch)

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📌 Important Reactions to Remember

1. H₂ + Cl₂ → 2HCl

2. 3H₂ + N₂ → 2NH₃ (Haber Process)

3. Zn + 2HCl → ZnCl₂ + H₂↑

4. CuO + H₂ → Cu + H₂O

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🔥 Extra Tips for Exams

Always remember the isotopes and their properties.

Learn industrial methods of preparation.

Focus on uses and chemical reactions.

Revise hydrides and their types (ionic, covalent, metallic).

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🎯 Final Words:

Hydrogen is not just the first element, it's the most fundamental! Mastering this chapter will build your base for upcoming topics like acids-bases, water, ammonia, and environmental chemistry.

Keep supporting us for more amazing notes! 😊❤️

Together, we are on a mission to crack CEE! 🚀

#mission_cee #hydrogennotes #NEB #inorganicchemistry

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