Inorganic Chemistry - Hydrogen and its Compounds

Comprehensive vocabulary flashcards covering the isotopes, allotropic forms, preparation methods, and hydrides of Hydrogen as discussed in Inorganic Chemistry for Engineering and IT exams.

Protium ($H$)

An isotope of Hydrogen where $p = 1$, $e = 1$, and $n = 0$; it makes up approximately $99.98\%$ of natural Hydrogen.

Deuterium ($D$)

An isotope of Hydrogen characterized by having $1$ proton, $1$ electron, and $1$ neutron ($p = 1$, $e = 1$, $n = 1$).

Tritium ($T$)

A radioactive isotope of Hydrogen where $p = 1$, $e = 1$, and $n = 2$.

Ratio of Protium to Deuterium

In ordinary Hydrogen, the ratio of protium to deuterium is approximately $6400:1$.

ortho Hydrogen

A form of Hydrogen molecule where the spins of the two protons are in the same direction.

para Hydrogen

A form of Hydrogen molecule where the spins of the two protons are in the opposite direction.

Stability of Hydrogen Allotropes

ortho Hydrogen is more stable than para Hydrogen, as the para form always tends to revert to the ortho form.

Absolute Zero Allotrope

At absolute zero, only the para form of Hydrogen exists.

Atomic Hydrogen

A highly unstable form of Hydrogen ($Half-life = 0.3\,\text{sec}$) obtained by passing ordinary Hydrogen through an electric arc at $2000^\circ$.

Nascent Hydrogen

Newly born Hydrogen ($[H]$) produced in contact with the substance to be reduced; it is more active than ordinary Hydrogen but cannot be isolated.

Active Hydrogen

Form of Hydrogen obtained by subjecting molecular Hydrogen to silent electric discharge at temperatures of $60^\circ-80^\circ$.

Earth's Crust Occurrence

Hydrogen contains nearly $1.1\%$ of the earth's crust by weight.

Laboratory Preparation of $H_2$

The reaction of Zinc with dilute Sulphuric acid: $Zn + H_2SO_4 \rightarrow ZnSO_4 + H_2$.

Zinc Grade for $H_2$ Preparation

Pure Zn is not used for preparation; commercial or granulated Zinc is preferred.

Bosch Process

An industrial method to prepare Hydrogen from water gas ($CO + H_2$) using $Fe_2O_3$ as a catalyst and $Cr_2O_3$ as a promoter.

Lane's Process

The industrial preparation of Hydrogen by the reaction of steam on Iron: $Fe + H_2O \rightarrow Fe_3O_4 + H_2$.

Electrolysis Method (High Purity)

Very pure Hydrogen can be obtained by the electrolysis of a $Ba(OH)_2$ solution, as it is free from carbonates.

Invisible pale blue flame

The manner in which Hydrogen burns in air or oxygen.

Cryogenic fluid

Liquid Hydrogen ($liq.\,H_2$) acts as a cryogenic fluid at approximately $-250^\circ$.

Ionic (Saline) Hydrides

Salt-like hydrides formed by metals with low electronegativity values, such as $LiH$, $NaH$, and $CaH_2$.

Covalent (Molecular) Hydrides

Hydrides formed by elements with high electronegativity (non-metals) held by weak van der Waals forces, such as $NH_3$, $CH_4$, and $H_2O$.

Polymeric Hydrides

Complex hydrides like $LiAlH_4$ and $NaBH_4$.