How halides and sulphides form in organic chemistry?, Chemistry

Halides 

Transition metals react with halogens at high temperatures to form halides. These reactions have very high activation energies; therefore, high temperatures are required to start these reactions. However, once the reaction starts, the heat liberated is sufficient to sustain the reaction. The order of reactivity of different halogens decreases as:

Fluorides are usually ionic whereas chlorides, bromides and iodides are predominantly covalent. The covalent character increase in atomic mass of the halogen. For example, CuF2 is ionic while CuCl2 and CuBr2 are covalent consisting of infinite chains. Co-ordination number of copper in these compounds is six.

Fluorine brings about the highest oxidation state of the metal. This is due its small size and high electronegativity. Halides of metals in higher oxidation states are relatively unstable and get hydrolysed easily. For example,
                                         
TiCl4 + 2H2O  1729_halides.png  TiO2 + 4HCl

Sulphides

Sulphides of transition metals are prepared either by direct combination of sulphur with metals or by the reaction of H2S or Na2S with the solution of their salts. In sulphides, the oxidation state of metal is generally low because sulphur is a weak oxidising agent. These sulphides are generally coloured or black. For example, NiS, CoS and CuS are black, MnS is light pink and CdS is yellow. They are insoluble in water.

Example: classify the following oxides as acidic, basic and amphoteric:
                         
MnO, MnO2, Mn2O3, Mn3O4, Mn2O7.

Solution: Acidic oxide : Mn2O7
               
Basic oxides : MnO, Mn2O3
      
Amphoteric oxides: Mn3O4, MnO2.

 

 

 

Posted Date: 6/25/2012 8:27:53 AM | Location : United States







Related Discussions:- How halides and sulphides form in organic chemistry?, Assignment Help, Ask Question on How halides and sulphides form in organic chemistry?, Get Answer, Expert's Help, How halides and sulphides form in organic chemistry? Discussions

Write discussion on How halides and sulphides form in organic chemistry?
Your posts are moderated
Related Questions
Chemical properties of monohydric alcohols Characteristic reaction of alcohol are the reaction of the - OH group. The reactions of the hydroxyl group includes either cleavage o

The elements of first transition series from variety of oxides of different oxidation states having general formulae  MO, M 2 O 3 , M 3 O 6 , MO 2 , MO 3 . These oxides are gene


Types of polymerization  Sol. Types of polymerization: polymerization is a process in which the joining together of many small molecules to form very large molecule called po

ionization energy vary in 3d seris of d-block elements,how and why

Calculate de-Broglie wavelength of an electron travelling at 1% of the speed of light: (1) 2.73 x 10- 24                (2)  2.42 x 10 -10 (3)  242.2x 10- 10


1(a). In these reactions, I2 (in the iodine solution) has what oxidation number? 1(b). The iodine starch reaction that turns purple depends on iodine being in the I- state. Was

What do you understand by molar conductivity at infinite dilution

Hi, I was wondering what the structure of semi synthetic and synthetic polymers were? I have an assignment due tomorrow and I cannot find any information on them! Thanks