Lecture on Halogens

These flashcards cover key concepts and details from the lecture on halogens, including their properties, trends, uses, and historical contexts.

What are the elements in the seventh main group of the periodic table known as halogens?

Fluor, Chlor, Brom, Iod, Astat.

What is the trend in melting points among the halogens?

Melting points increase from Fluor (-220°C) to Astat (300°C).

What are the physical states of halogens at room temperature?

Fluor and Chlor are gases, Brom is a liquid, and Iod and Astat are solids.

Which halogen has the highest electronegativity according to Pauling scales?

Fluor has an electronegativity of 4.0.

What is the typical electron affinity trend among halogens?

Electron affinity decreases from Fluor (-3.4 eV) to Astat (-3.1 eV).

What type of bond do halogens typically form in compounds?

Halogens tend to form diatomic molecules (X2) in all states.

What is the significance of the term 'salzbildner'?

Halogens are known as 'salzbildner' or salt formers because they form ionic compounds as X− ions.

How is Fluor primarily extracted for industrial use?

Fluor is extracted from calcium fluoride (CaF2) using concentrated sulfuric acid.

What is the most important method for the production of Chlor?

Chloralkali electrolysis is the most common method for producing chlorine.

What are some of the uses of Chlor?

Chlor is used for the production of chlorinated hydrocarbons, water bleaching, and catalysis.

What was the historical significance of Chlor in warfare?

Chlor was used as a chemical weapon during World War I.

What is the main distinction in the chemistry of Brom and Iod compared to Chlor?

Brom and Iod react similarly to Chlor but are milder in their reactivity.

What is the effect of Iodine deficiency in humans?

Iodine deficiency can cause conditions like struma and cretinism.

What is the common laboratory use of Lugol’s solution?

Lugol’s solution (I2 + I−) is used as a reagent in various chemical and biological experiments.

What is the characteristic property of interhalogen compounds?

All interhalogen compounds are highly toxic.

What is a significant property of perchlorates in rocketry?

Ammonium perchlorate is a primary component in rocket propellants.