--%>
Assignment Help - homework help

Explain physical properties of haloarenes.

. Boiling points

The boiling points of monohalogen derivatives of benzene, which are all liquids, follow the order

Iodo > Bromo > Chloro

The boiling points of isomeric dihalobenzenes are nearly the same. However, their melting points are fairly dissimilar. The melting point of para isomer is generally 70-100 degrees higher than the melting points of ortho and meta isomers. The higher melting point of para isomer is due to its symmetry which leads to more close packing of its molecules in the crystal lattice and consequently strong intermolecular attractive forces.

Boiling point:    453 K              446 K            448 K

Melting point:   256 K              249 K            323 K

2. Solubility

Haloarenes are insoluble in water, acids or bases but are soluble in organic solvents.

Haloarenes are insoluble in water because they cannot form hydrogen bonds with water molecules.

3. Density 

These are all heavier than water. Their densities follow the order given below.

Iodo > Bromo > Chloro

   Related Questions in Chemistry

  • Q : What do you mean by the term hydra What

    What do you mean by the term hydra? Briefly define it.

    		•
  • Q : Composition of the vapour Choose the

    Choose the right answer from following. An ideal solution was obtained by mixing methanol and ethanol. If the partial vapour pressure of methanol and ethanol are 2.619KPa and 4.556KPa respectively, the composition of the vapour (in terms of mole fraction) will be: (

    		•
  • Q : Number of electrons in the benzene

    Describe the number of electrons in the benzene? Write a short note on it?

    		•
  • Q : F-centres If a electron is present in

    If a electron is present in place of anion in a crystal lattice, then it is termed as: (a) Frenkel defect  (b) Schottky defect  (c) Interstitial defects (d) F-centre Answer: (d) When electrons are trapped in anion vacancies, thes

    		•
  • Q : Question of vapour pressure Choose the

    Choose the right answer from following. Vapour pressure of a solution is: (a) Directly proportional to the mole fraction of the solvent (b) Inversely proportional to the mole fraction of the solute (c) Inversely proportional to the mole fraction of the solvent (d

    		•
  • Q : What are aliphatic amines and its

    In common system, the aliphatic amines are named by using prefix for alkyl group followed by the word amine.In case of mixed amines, the name of alkyl groups are arranged in alphabetical order. This is followed by the word amine. However, for simple secondary or tertiary amines anothe

    		•
  • Q : Hybridization Atomic orbitals can be

    Atomic orbitals can be combined, in a process called hybridization, to describe the bonding in polyatomic molecules. Descriptions of the bonding in CH4 can be used to illustrate the valence bond procedure. We must arrive a

    		•
  • Q : Neutralization of sodium hydroxide How

    How much of NaOH is needed to neutralise 1500 cm3 of 0.1N HCl (given = At. wt. of Na =23): (i) 4 g  (ii) 6 g (iii) 40 g  (iv) 60 g

    		•
  • Q : What is Henry law constant and its

    1. The units of Henry Law constant are same as those of pressure, i.e. torr or h bar. 2. Different gases have dissimilar values of Henry law constant. The values of KH for some gases in water are given in tabl

    		•
  • Q : Calculating value of molar solution

    Choose the right answer from following. An X molal solution of a compound in benzene has mole fraction of solute equal to 0.2. The value of X is: (a)14 (b) 3.2 (c) 4 (d) 2

    		•