Question

Correct order of bond angles in nh3 pcl3 bcl3

Answer 1

first calculate hybridisation of central atom

then subtract hybridisation and no. of surronding atoms

which will give no. of lone pairs

we know that bond angle inversely proportional to lone pairs

for nh3

we have 1 lone pair

for pcl4

we have 1 lone pair

for bcl3

we have 0 lone pair

and we can see same lone pairs for both nh3 and pcl4

in this case main atom is same you should take atoms which has less electro negativity

which means h has less electro negativity means it has more bond angle

so the final order is bcl3,nh3 and pcl4

note this is increasing bond order