How halides and sulphides form in organic chemistry?, Chemistry


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 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
Dielectric loss: These losses occur because of electrons hopping from single lattice site to another in transition metal oxides.

how trans uranium elements are seperated by solvent extraction

Drugs - Chemistry in Action Drugs may be a single chemical atom or a combination of two or more dissimilar substances. An perfect drug should assure the following needs, Whi

i need help finding information with the element sodium

Dual nature of particles was proposed by: (1) Heisenberg (2) Lowry (3) de-Broglie     (4) Schrodinger Ans:de-Broglie

Q. Explain about Magnetic Separation ? This process is based on the difference in magnetic properties of minerals. If the ore but not the gangue is attracted by a magnetic fiel

discuss in detail the basic principle and instrumentation involved in fluorimetry and phosphorimetry

What are laws of crystallography?How it helps us in the study of crystal structure

150ml of a gas at 27C is heated to 77C at constant pressure.find the new volume of the gas.

Magnesium is the lightest of the structural metals. While this low density is an attractive property, magnesium also has a high corrosion rate that has often been seen as a disadva