easechemistry

 Recall that it is the molecular weight and extent of intermolecular forces which determine physical states( solid, liquid and gas) of substances.  Order of Intermolecular forces strength in substances is : Solids>liquid>gases When we look at molecular weight , it seems water would be in gaseous state and hydrogen sulfide be in liquid state. But here in case of water , water has hydrogen bonding . Hydrogen bonding is limited to  three highly electronegative atoms ( F, O and N). In water H2O, Hydrogen is attached to 2nd highest electronegative atom i.e O of periodic table.Hence water is having relatively strong intermolecular forces in form of hydrogen bonding. On other hand Hydrogen sulphide is having simple dipole-dipole interaction. Order of intermolecular forces in strength is  Hydrogen Bonding> dipole-dipole forces> London forces  Hydrogen bonding among water H2O molecules On other hand Hydrogen sulphide is having simple dipole-dipole interactio...

  Here first of all recall the definition of an acid.According to Arrhenius concept, Acid is a species which can produce protons (H +)  in its aqueous solution. Now its easy to understand that which species gives more protons will be more strong acid. Hydrogen flouride (HF) is having strong hydrogen bonding , as fluorine is highly electronegative atom and offers strong  Hydrogen bonding. Due to this hydrogen bonding , hydrogen is tightly trapped between two highly electronegative F atoms. Such entrapped H + are difficult to be free. On the other hand HCl molecule is having dipole- dipole intermolecular force which is weaker than hydrogen bonding so H + entrapped between two Cl atoms are easy to get free. Hence these are the type of intermolecular forces - hydrogen bonding in HF and simple dipole -dipole forces in HCl - which are making HCl stronger acid than HF.