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Chemistry formula for class 11 chapter- P-Block Elements

Chemistry Formulas

Class 11 chapter- P-Block Elements

  • Boron, Aluminium, Gallium, Indium and Thalium belong to IIIA group of the periodic table.
  • B and Al show similar properties due to similar outer E.C.
  • Atomic radius increases suddenly from B to Al. This is due to the greater screening effect of electron present in the (n – 1) shell.
  • The atomic radii of Al is greater than Ga. This is because of the poor shielding effect of d-electron of Gallium.
  • Gallium exists as liquid between 29.8°C and 2000°C.
  • The low melting point of Ga is due to its simple molecular structure. It consists of Ga2 molecules.
  • The most electro positive element in IIIA group is Al.
  • Boron exhibits –3 and +3 oxidation states.
  • Due to inert pair effect +1 oxidation state of Thalium is more stable.
  • The Trihalides of B and Al are covalent, electron deficient and can act as Lewis acids.
  • 95 – 98% pure Boron is obtained on reducing B2O3 with Mg or Na metal at high temp. It is known as Moissan Boron.
  • Boron is non-conductor of electricity.
  • Boron in non-conductor of electricity.
  • Boron carbide is the hardest compound of Boron. Its formula is B4C3.
  • Borax is Na2B4O7.10H2O (Tincal).
  • Borax is available in nature as Kernite (Na2B4O7.4H2O) (Rasorite)
  • Borax bead test : On heating borax it swells into a white, opaque mass of anhydrous sodium tetra borate. When it is fused, borax glass (NaBO2 + B2O3) is obtained.
  • The hydrides of Boron are called boranes.
  • These are electron deficient molecules.
  • The general formula of boranes
  1. BnHn+4
  2. BnHn+6
  • Diborane (B2H6) is an electron deficient molecule
  • Preparation of diborane :

preparation of dibrone

  • Properties of diborance :

preparation of dibroce

  • The hybridization of Boron in diborane is Sp3.
  • In B2H6, the four hydrogen atoms lie in one plane are called terminal hydrogen atoms and the remaining two hydrogen atoms are called bridge hydrogen atoms.
  • The bridge hydrogen atoms are involved in three centered two electron bond called banana bond (or) Tau bond.

Do follow NCERT text book and solve questions with the help of Physics Wallah NCERT solutions for class 11 chemsitry

Download free pdf sheet which consist of formulas and important points of P-Block Elements from the link given below

Chemistry formula for class 11 chapter- P-Block Elements

Chemistry formula for class 11 chapter- P-Block Elements

Chemistry formula for class 11 chapter- P-Block Elements

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