Groups 14 to 17 - 28.01.26

This set of flashcards provides definitions and explanations of key vocabulary terms related to chemistry concepts discussed in the lecture.

Hydrogen Bonding

A type of weak chemical bond that occurs when a hydrogen atom covalently bonded to an electronegative atom experiences attraction to another electronegative atom.

Haber Process

An industrial process to synthesize ammonia from nitrogen and hydrogen, crucial for fertilizer production.

N₂ + 3H₂ → 2NH₃

Covalent Bonding

A type of bonding where atoms share pairs of electrons.

Oxidation State

The charge of an atom in a compound, indicating the extent of oxidation or reduction.

Semiconductor

Materials with electrical conductivity between a conductor and an insulator, crucial for electronic devices.

What are some key features of N?

• N₂ = inert gas

• makes up 78% of atmosphere

• weak intermolecular forces → b.p. = -200 C

What is the general formula of reactions between G5 members & halogens?

2E + 3X₂ → 2EX₃

and furthermore: EX₃ + X₂ → EX₅

Why does NH₃ have higher m.p./b.p. than other G5 hydrides?

due to hydrogen bonding

What do NO_x gases refer to?

nitrogen oxides that form in various stoichiometric ratios

→ are a feature of urban smog and acid rain

What are some biologically relevant examples of NO_x gases?

1. NO (a free radical) = role in blood clotting & control of blood pressure

2. NO (nitrous oxide) = mild anaesthetic in dentistry

What is the difference between white phosphorous and red phosphorous?

white:

• white, waxy solid

• mp = 44

• stored under water → bursts into flames in air

• P₄ tetrahedra

red:

• red powder

• mp = 600

• stable, non-toxic

• polymeric chains of P₄

How does P typically react with halides?

forms trihalides or pentahalides

*forms hypervalent covalent bonds

Does P act like a Lewis acid or base and why so?

• acts like a Lewis acid

• due to empty d orbitals

What is a Lewis acid?

a substance that can accept a pair of electrons

What is a Lewis base?

a substance that can donate a pair of electrons

What are some features and applications of As?

features = metalloid, covalent & ionic species

app. = poison, once used as treatment for syphilis

What are some medicinal applications of Bi?

• antacids (e.g. peptobismol)

• anti-H. pylori drugs

What are the most common oxid. states of G5 members?

+3 or +5

How do other members of G6 react with O₂?

are oxidised by it

What is the importance of oxygen for humans?

makes up:

1. 50% of earth’s crust

2. 65% of human body

3. 21% of atmosphere