Softinn

Q - 2)    What is nascent hydrogen? Describe its reactivity: Nascent Hydrogen:                           Hydrogen at a time of its birth is chemically more reactive than molecular hydrogen because it is available in atomic form and known as Nascent Hydrogen or Newly born hydrogen. Reactivity:                         When a piece of Zn metal adds in the acidic Ferric chloride (FeCl 3 ) solution, nascent hydrogen is generated which reduces FeCl 3 into ferrous chloride (FeCl 2 ) which is greenish in colour. FeCl 3(aq) + H 2(g) No reaction ­ Zn/HCl FeCl 3(aq) +  [H] FeCl 2(aq) + HCl (aq) Nascent Hydrogen Ferrous Chloride Acidic KMnO 4 (pink) solution can be reduced by nascent hydrogen to colou

Chemical Properties of Hydrogen: 1.   Decomposition of molecular Hydrogen (H 2 ) Molecular hydrogen contains stable covalent bonding and is relatively inert at ordinary conditions. Its bond dissociation energy is 104 K.cals/mol. H — H H + H  r H = 104 K.cals/mol.    i.e +435 KJ/,mol. Q. Show hydrogen is a good reducing agent: 2.   As a reducing Agent Hydrogen shows greater affinity for oxygen and reduces many metal oxides into free metals. CuO (s) + H 2(g) Cu (s) +3H 2 O (g) ­ WO 3(s) + 3H 2(g) W (s) + 3H 2 O (g) 1.   Hydrogenation Reaction: The addition of hydrogen into other molecular compounds called hydrogenation reaction. When molecular compounds and Hydrogen are heated in the presence of Pt or Pd or Ni and other crystals