Chemical Bonding and Molecular Structure

Which among the following molecules is (a) involved in sp3d hybridization, (b) has different bond lengths and (c) has lone pair of electrons on the central atom?

1. XeF4
2. XeF2
3. PF5
4. SF4

An element 'E' has the ionisation enthalpy value of 374 kJ mol-1. 'E' reacts with elements A, B, C and D with electron gain enthalpy values of −328, −349, −325 and −295 kJ mol-1, respectively. The correct order of the products EA, EB, EC and ED in terms of ionic character is :

1. EB > EA > EC > ED
2. EA > EB > EC > ED
3. ED > EC > EA > EB
4. ED > EC > EB > EA

The sum of sigma ( ) and pi ( ) bonds in Hex-1,3-dien-5-yne is .

The molecules having square pyramidal geometry are

1. BrF5 & PCl5
2. SbF5 & PCl5
3. BrF5 & XeOF4
4. SbF5 & XeOF4

Total number of molecules/species from the following which will be paramagnetic is . O2, O2+, O2-, NO, NO2, CO, K2[NiCl4], [Co(NH3)6]Cl3, K2[Ni(CN)4]