Chemicals Talk

  Oxides of nitrogen are a mixture of gases that are composed of nitrogen and oxygen. At high-temperature oxygen and nitrogen undergo an   endothermic   reaction producing various oxides of nitrogen but oxygen and nitrogen cannot react at low temperature. The general term for nitrogen oxide is denoted NOx. The term NOx is common means that molecule containing one nitrogen and one or more oxygen atoms, but actually, it is a mixture of NO (nitric oxide) and NO 2 . Different types of oxides of nitrogen are present in this environment they have a valence state from 1 to 5 for example : Nitrous oxide (N 2 O) Nitric oxide (NO) Dinitrogen dioxide(N 2 O 2 ) Dinitrogen trioxide (N 2 O 3 ) Nitrogen dioxide (NO 2 ) Dinitrogen tetroxide(N 2 O 4 ) Dinitrogen pentoxide(N 2 O 5 ) All NOx gases are harmful to human health and the environment. The environmental pollutants under the oxides of nitrogen include nitrous oxide(N 2 O), nitric oxide (NO) and nitrogen dioxide(NO 2 ).nitric o...

  These elements are called the   nitrogen family .  It consists of   nitrogen , phosphorus, arsenic, antimony,  bismuth, and meconium. They are present on the right side of the periodic table.  All the elements are arranged based on their atomic weight. The elements with similar properties reside in a column called the group. Trends in Group 15 Elements 1) Electronic configuration  These group elements have a general electronic configuration which is ns 2 np 3 . As all have the same  valence electronic configuration , they belong to the same family. Their s-orbital always remains occupied by electrons, but the p-orbital is half-filled. That is why they are very stable elements. 2) Atomic radii and ionic radii Atomic radii, as well as ionic radii, increase if we go from the upper elements to the lower elements. It is because of adding an extra electronic orbital. But in the case of arsenic and bismuth, this increment is not that much because ...

  Haloalkanes   Haloalkanes These have hydrocarbons made up with  aliphatic  alkanes and one or more hydrogen atoms replaced by  halogens  (elements such as Chlorine, Bromine, Fluorine, Iodine etc.). Here, the halogen atom is attached to the sp 3  hybridized carbon atom of the alkyl group. Example:  CH 3 Cl (Methyl Chloride)                           CH 3 CH 2 Br (Ethyl Bromide) These are saturated organic compounds where all the chemical bonds are attached to the carbon atom with single bonds and a single carbon atom is attached to the Halogen atom. Haloalkanes are made by aliphatic alkanes by the process of free radical halogenation. They are odourless compounds. These precipitate in SN 2  substitution reactions. Haloarenes Haloarenes are hydrocarbons consisting of  aromatic  ring/rings and one or more  hydrogen  atoms replaced by halogens. The halogen atom...

  Ideal and Non-Ideal Solution  A homogeneous mixture composed of two or more components is called a Solution. The component which has the highest quantity in a solution is the solvent. The solvent helps determine the physical state of the solution. A solute is a substance, in a solution, found in a smaller amount. The solution that has two components is called a  Binary Solution . The properties of a solution are further defined on basis of the Vapour Pressure, Boiling Point, Freezing Point and other Colligative Properties. The binary liquid in liquid solutions can be further divided into two terms: Ideal Solution Non-ideal Solution Ideal Solution The solutions which follow Raoult's law at all temperatures and concentrations are called  Ideal Solution . During its formation no change in enthalpy or volume takes place. In ideal solutions, the interaction between solute-solute and solvent-solvent molecules same as the interaction between solute and sol...

Raoult's law According to Raoult's law,  “the vapour pressure of any solution containing a non-volatile solute in a volatile  solvent  is proportional to the mole fraction of the solvent in the solution.” Raoult's law was first given by French chemist François-Marie Raoult in the year 1887. It is applicable for a solution of two volatile liquids. It claims that the  vapour pressure  of the solution is proportional to the mole fraction of the solvent. Thus, Raoult’s Law formula is:   P = P 0 X     Thus, P solution  = Χ solvent .P solvent Where, P solution  = Vapor pressure of the solution Χ solvent  = Mole fraction of the solvent P solvent  = Vapor pressure of the pure solvent Example of Raoult’s Law Assume a solution of volatile liquids A and B in a given beaker. Since both A and B are volatile, both particles A and B are in the vapour phase. Consequently, the vapour particles of A and B thus exert partial pressu...

  COLLOIDS  Colloids, which are also known as colloidal solutions or colloidal systems are mixtures in which micro-insoluble particles of one substance are suspended in another substance. Suspended particles in a colloid can range from 1 to 1000 nanometres that is 10 –9  metre in size. Colloids usually contain substances that are evenly scattered in another. In such a mixture, the material that is dispersed is called dispersed state whereas the material through which it is dispersed is called  continuous phase . Classification of colloids Colloids are classified into several types. Classification based on physical condition (A) Solid Solution-  Solids and dispersion medium in this scattered phase. Such as: Gemstone. (B) Aerosol-  These colloids contain air as the dispersion medium. Example 1: Cloud- It consists of air as the dispersion medium and water droplets as the dispersion phase. Example 2: Dust-. It consists of air  dispersion  medium ...