Group VII Elements - Chemistry Review

A comprehensive set of flashcards covering key concepts related to Group VII Elements (halogens) and their properties, reactions, and significance in chemistry.

Group VII Elements

Also known as halogens, which include fluorine, chlorine, bromine, iodine, and astatine.

Oxidising Agents

Substances that accept electrons in a chemical reaction, becoming reduced in the process.

Volatility

The tendency of a substance to vaporize; it decreases down Group VII due to increasing molecular size.

Disproportionation

A chemical reaction in which one species is simultaneously oxidized and reduced.

Thermal Stability of Hydrides

The stability of hydrides decreases down the group as atomic size increases, leading to weaker bonds.

Bond Energy

The measure of bond strength in a chemical bond; decreases down Group VII as bond lengths increase.

Electronegativity

The tendency of an atom to attract electrons in a bond; decreases down Group VII.

Hydrogen Halides

Compounds formed by the reaction of hydrogen with halogens, typically gaseous at room temperature.

Reactivity Trend

Reactivity of Group VII elements decreases down the group as atomic size and shielding increase.

Displacement Reaction

A reaction where a halogen displaces a halide ion from a compound due to differing oxidizing strengths.

Test for Halides

Involves adding silver nitrate to form precipitates, which indicate the presence of halide ions.

Bond Enthalpy of Hydrogen Halides

Decreases down the group, making acids stronger as bond energies weaken.

Chlorine in Water Treatment

Chlorine is used as a disinfectant due to its ability to kill bacteria, often in swimming pools.

Hydrogen Reaction with Halogens

Hydrogen reacts with halogens to form halides, often requiring specific conditions such as UV light.

Halogen Physical Properties

As we move down the group, physical state changes from gas to liquid to solid with increased atomic number.

Changes in Oxidation Numbers

Important in reactions involving chlorine and its compounds, particularly with cold water and alkali.