Question

Define and provide examples of the following terms

(a) aromatic (b) hydrophilic (c) combustion

(d) methylene group (e) methyl group (f) common name

(g) IUPAC name (h) conformations (i) Newman projection

(j) eclipsed (k) staggered   (l) gauche conformation

(m) anti conformation (n) catalytic cracking (o) cis-trans isomers of a ring

(p) chair conformation (q) boat conformation   (r) distorted boat

(s) half chair conformation (t) axial position (u) equatorial position

(v) chair-chair interconversion (w) fused ring system (x) bridged bicyclic compound

(y) bridgehead carbon atoms

Answer 1

a - Aromatic :

  A aromatic compound refers to an organic compound which has (2n + )electrons with cyclic conjugate structure.

The molecule should be flat.

Example : Benzene and napthalene.

b - Hydrophilic :

If a compound is readily dissolved in water and water solvents , then it is called as a hydrophilic molecule.

Most of the polar groups which resembles H -OH are hydrophilic, such as alcohols (R-OH) and carboxylic acid (CO-OH)

Other examples of hydrophilic group are : -NH , -NO₂ , -CN etc.

c- Combustion :

Combustion is a chemical reaction between oxygen and a substance which gives up heat and light.

All combustion reactions are exothermic.

Examples :

i- Combustion of methane to give CO₂ and water.

CH₄ + O₂ -------> CO₂ + H₂O , H = -ve

ii- Rusting of Iron

3Fe + 4O₂ -------> Fe₃O₄  

d- Methylene group:

  Methylene group is apart of a molecule that is connected to the rest of the part by two single bond.

(CH₂= or  -CH₂-)

Example :i- CH₃ - CH=CH₂ (propene)

Here =CH₂ is the methylene group

ii- CH₃-CH₂-CH₃ (propane)

Here -CH₂- is the methylene group