Redox reaction

Redox reaction:

  • Reactions which can be explained on the basis of gain or loss of electrons is called redox reactions.
  • In molecular compounds, the combining capacity i.e. the valency of each combining element determines the chemical formula of the compound.
  • The valency of an electropositive ion and an electronegative ion is equal to the positive or negative charge on it.
  • Reactants are substances that take part in a chemical reaction, while products are the new substances produced during the chemical reaction.
  • When two or more elements or compounds react chemically to form one new compound, then the chemical reaction that takes place is a chemical combination reaction.
  • When a chemical compound decomposes on heating or by some other way so as to form two or more compounds or elements then the reaction that takes place is called chemical decomposition.
  • When a more active metal or nonmetal displaces a less active element from its aqueous salt solution, the reaction that takes place is called displacement or substitution reaction.
  • A chemical reaction in which two ionic compounds in their aqueous solutions react by exchanging their ions/radicals to form to two new compounds is called chemical double decomposition.
  • A polymerization reaction is one in which two or more molecules (monomers) combine to form a new bigger molecule.
  • Chemical equations can be made more informative by indicating physical states, heat changes and condition under which the reaction takes place.
  • A reaction in which heat is given out is exothermic. DH is negative
  • A reaction in which heat is taken in is called endothermic. DH is positive.

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