Why does bond angle of hydrides decrease down the group?

Why does bond angle of hydrides decrease down the group?

The hydrides of group 15 are strong reducing agents. These hydrides are pyramidal in shape with a lone pair of electrons in one of the orbits. The bond angle gradually decreases down the group due to the decrease in bond pair- bond pair repulsions.

What causes bond angles to decrease?

i) The bond angle decreases due to the presence of lone pairs, which cause more repulsion on the bond pairs and as a result the bond pairs tend to come closer. The bond pairs tend to move away from each other since the distance between them is shortened as they are more localized on more electronegative central atom.

Why do bond angles decrease in group 16?

The bond angle in the hydrides of the group 16 decreases as we go down the group. As electronegativity falls down the group, the tendency of the central atom to attract bond pair of electrons falls thus making lone pair – lone pair repulsion more important and thereby reducing the bond angle.

What can affect bond angle?

Many factors lead to variations from the ideal bond angles of a molecular shape. Size of the atoms involved, presence of lone pairs, multiple bonds, large groups attached to the central atom, and the environment that the molecule is found in are all common factors to take into consideration.

What are the factors that affect bond angle?

What factors affect bond angles?

(i) Repulsion between atoms or groups attached to the central atom may increase or decrease the bond angle. (ii) In hybridisation as the s character of the s hybrid bond increases, the bond angle increases. (iii) By increasing lone pair of electron, bond angle decreases approximately by 2.5%.

Which hydride has largest bond?

H2O
H2O has the largest bond angle among VIA group hydrides. The reason is the high electronegativity of oxygen atom due to which bonding electron pair remains closer to oxygen atom in H2O molecule. Hence, the repulsion between bonding e− is maximum in H2O due to which the bond-angle is maximum (104.5°) in H2O .

Which hydride has the highest bond angle?

ammonia
> Among group 15 hydrides, ammonia has the highest bond angle. The small sized nitrogen atom in ammonia has the highest electron density.

How does bond angle depend on electronegativity?

The bond angle is inversely proportional to the electronegativity of the substituents. A more electronegative substituent , pulls the electrons towards itself thus decreasing the charge density on the central atom. This results in decrease in bond angle.

How bond angles are determined?

The bond angles depend on the number of lone electron pairs. Water, with two lone pairs of electrons, has a bent shape with 104.5-degree bond angles. The VSEPR theory assumes that each atom in a molecule will achieve a geometry that minimizes the repulsion between electrons in the valence shell of that atom.

Why does bond angle decrease down the group 16?

-The lone pair – bond-pair repulsion is stronger is than lone pair-lone pair or bond pair bond-pair interaction. -But as the electronegativity decreases, the repulsion also decreases which results in a decrease in bond angle. The Bond Angle decrease as we move down the16 group. refer to photo

Why is the H-M-H bond angle lower in hydrides?

The hydrides have a pyramidal or tetrahedral shape with a lone pair of electrons In one of the orbitals. The H – M – H bond angle is less than the original 109o28′ tetrahedral bond angle (H -N -H in N H 3 is 106o45′) because of greater repulsion between one pair an a on pair than between two bond pairs of electrons.

Why does basicity of Group 15 hydrides decrease?

So even though the EN difference between N and P is significant, when hybridization differences of the central atom are taken into account the electron density argument still explains the trend in basicity. The hydrides of nitrogen family have one lone pair of electrons on their central atom.

How many bond pairs are in Group 16 hydrides?

Group 16 hydrides have tetrahedral geometry with 2 lone pairs and 2 bond pairs. You know that lone pair-bond pair repulsions are stronger than bond pair-bond pair repulsions.