1

### NEET 2016 Phase 1

Consider the molecules CH4, NH3 and H2O.

Which of the given statements is false?
A
The H $-$ O $-$ H bond angle in H2O is smaller than the H $-$ N $-$ H bond angle in NH3.
B
The H $-$ C $-$ H bond angle in CH4 is larger than the H $-$ N $-$ H bond angle in NH3.
C
The H $-$ C $-$ H bond angle in CH4, the H $-$ N $-$ H bond angle in NH3, and the H $-$ O $-$ H bond angle in H2O are all greater than 90o.
D
The H $-$ O $-$ H bond angle in H2O is larger than the H $-$ C $-$ H bond angle in CH4.

## Explanation In CH4, there is no lone pair of electrons so it is perfectly tetrahedral in shape and has H-C-H bond angle of 109°28′ but in NH3 there is one lone pair which due to more repulsion with bond pairs of electrons pushes them more closer thus bond angle decreases to 107°. In H2O, there are two lone pair of electrons which suppress the bond angle more to 104.5°.
2

### NEET 2016 Phase 1

Predict the correct order among the following :
A
bond pair - bond pair > long pair - bond pair > lone pair - lone pair
B
lone pair - bond pair > bond pair - bond pair > lone pair - lone pair
C
lone pair - lone pair > lone pair - bond pair > bond pair - bond pair
D
lone pair - lone pair > bond pair - bond pair > lone pair - bond pair

## Explanation

According to VSEPR theory, the repulsive forces between lone pair and lone pair are grater than between lone pair and bond pair which are further greater than bond pair and bond pair.
3

### NEET 2016 Phase 2

Among the following, which one is a wrong statement ?
A
PH5 and BiCl5 do not exist.
B
p$\pi$-d$\pi$ bonds are present in SO2.
C
SeF4 and CH4 have same shape.
D
I3+ has bent geometry.

## Explanation 4

### NEET 2016 Phase 2

The correct geometry and hybridization for XeF4 are
A
octahedral, sp3d2
B
trigonal bipyramidal, sp3d
C
planar triangle, sp3d3
D
square planar, sp3d2

## Explanation sp3d2 hybridisation (octahedral geometry, square planar shape)