Definitions by chemguide

Aromatic compound 

some kind of compounds containing conjugated double bonds, like benzene.

According to Huckel's rule, aromatic compound needs following properties:
-The structure is planar (no sp3 carbons)
-There is a cyclic ring in the structure
-Has 4n+2 electrons in the pi system

Aromatic compound by chemguide August 12, 2019

cyclohexane 

The most stable cycloalkane. It has a 6-membered carbon ring with all hydrogen atoms surronding it

Cyclohexane also has 2 conformers: chair and boat. The chair conformer is more stable because of its reduced strain.

cyclohexane by chemguide August 12, 2019

Cyclopentadiene 

An hydrocarbon compound that is basically violating being a hydrocarbon. Its pKa value is only 16, making it as acidic as water.
Its structure is a cyclopentane ring with 2 double bonds.

The reason for cyclopentadiene to be such acidic is because of its ionic structure. It has an aromatic anionic structure, making it extremely stable.

Cyclopentadiene by chemguide August 12, 2019

chemophobia

The fear of chemistry/ chemicals. The actual truth is that chemicals are everywhere, including water. Unfortunately, people make 'chemical-free' stuffs (which is wrong). This problem, therefore, should be fixed.

Just see how strong your chemophobia is.
Do you know that dihydrogen monoxide is now found in every water source? Its gas and solid state can burn people! And it is the main component of acid rain! You want to ban it?
Actually it is water.

chemophobia by chemguide August 11, 2019

The dose makes the poison 

Everything in the world is harmful if in large amounts, and this includes all-natural fruits, water, etc. , because the dose (amount) makes the poison (lethal).

Ad: "No artificial sweeteners, all-natural! Detox drink"
Me: "The dose makes the poison, do you know that everything can be toxic?"

The dose makes the poison by chemguide August 11, 2019

theophylline 

A dimethyl derivative of xanthine, structurally similar to theobromine.

Theophylline is used in therapy for respiratory diseases.

theophylline by chemguide August 11, 2019

methyl orange 

A pH indicator (most commonly) used in acidic conditions.

In acidic conditions methyl orange is red but in neutral / basic conditions it is yellow.

methyl orange by chemguide August 11, 2019