IIT JEE , AIEEE Forum - Chemistry , Organic Chemistry

jssrk

Plz explain abt the lone pair in water and ammonia regarding hybridisation.

aankurverma

in NH3 N has a lone pair n H2O O has lone pair

n dey bot r in dynamic equilibrium

NH3 + H2O => NH4+ + OH-

hope u got it

astronautameya

well..... we have three kinds of compounds in the p-block.

e- deficient( BH3) lewis acid
e- precise ( CH4)
e- rich ( NH3, H2O....) lewis base

NH3 is sp3 hybridized ...... so the lone pair is in tetrahedral geometry(distorted).

astronautameya

hey ankur verma..... plz dont answer if youre not sure........

H2O has TWO lone pairs....... if it had zero, then it wud have linear shape...... but it is distorted......

aankurverma

hey dude beter read my reply i hav just type is O has lone pair nor dat O has a lone pair

n do chk it once again

n yeah don wrry i m sure abt my answers

jssrk

Iam telling abt the lone pair of NH3 n H2O regrdng hybridisation

m.viddya

Structure of Ammonia:

The bonds in ammonia can be explained by sp3 hybridization.the electronic conf. of nitrogen is 1s2 2s2 2px 2py 2pz.the s orbitalof 2s and 3 porbitals of nitrogen intermix and reshuffle into 4 new identical sp3 orbitals,thus nitrogen undergoes sp3 hybridization.one of these orbitals contains a lone pair and the other 3 orbitals have one electron each.these orbitals form sigma sp3-s bomds by overlapping with 3 s orbitals of the 3 hydrogen atoms.the bond angle is expected 2 be 109deg28'..but due to the repulsions between the lone pair and bond pairs the angle reduces to 107deg.the molecule assumes a trigonal bipyramidal shape rather than a tetrahedral shape.

pl rate if found useful

m.viddya

Formation of water molecule:

The central atom in water molecule is oxygen .oxygen has the configuration 1s2 2s2 2px 2py 2pz.the oxygen atom undergoes sp3 hybridization by intermixing of s and 3 p orbitals and reshuffling into 4 identical orbitals.2 of these are occupied by lone pairs and the remaining by 1 electron each.these orbitals containing single electron overlap with the s orbitals of 2 hydrogen atoms and form 2 sigma sp3-s bonds.lone pair-lone pair repulsions reduce the tetrahedral bond angle to 104deg30'.it is described as an angular molecule.

pl rate if the inf. is useful

punnima

If lone pair electrons are present on the central atom, these can occupy one or more of the sp3 orbitals. This causes the molecular geometry to be different from the coordination geometry, which remains tetrahedral.

In the ammonia molecule, for example, the nitrogen atom normally has three unpaired p electrons, but by mixing the 2s and 3p orbitals, we can create four sp3-hybrid orbitals just as in carbon. Three of these can form shared-electron bonds with hydrogen, resulting in ammonia, NH3. The fourth of the sp3 hybrid orbitals contains the two remaining outer-shell electrons of nitrogen which form a non-bonding lone pair. In acidic solutions these can coordinate with a hydrogen ion, forming the ammonium ion NH4+. Although no bonds are formed by the lone pair in NH3, these electrons do give rise to a charge cloud that takes up space just like any other orbital.

In the water molecule, the oxygen atom can form four sp3 orbitals. Two of these are occupied by the two lone pairs on the oxygen atom, while the other two are used for bonding. The observed H-O-H bond angle in water (104.5°) is less than the tetrahedral angle (109.5°); one explanation for this is that the non-bonding electrons tend to remain closer to the central atom and thus exert greater repulsion on the other orbitals, thus pushing the two bonding orbitals closer together.

hope u understood.....

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