Question

10.What is hydrogen bonding?

11.How do colligative properties affect freezing point?

12.What hybrid orbitals would be in CH₄?

Answer 1

10. Hydrogen Bonding:

This is a non bonding interactions between H-atom when bonded to highly negative atom like, O, N or F and another elctronegative atom. For example, water, H2O exhibits tremenedous hydrogen bonding, which makes it a liquid at normal temperature. H-O-H----H-O-H---H-O-H, actually it extends to threedimentional space. Hydrogen bonding can change the property of any molecule drastically. For examplr H2S though having higher molar mass but it is a gas at STP because there is no hydrogen bonding but H2O though a smaller and less molar mass is a liquid through hydrogen bonding. Another example, H-F----H-F---H-F etc.

11. There will be a depression in freeing point when solutes add to the solvent. It depends on the molality of the solute. delta Tf = delta Tf (solvent) - Tf(solution) =Kf.m where, Kf = freeing point depression constant. m=molality.

12. In CH4, C is sp3 hybridized, tetrahedral in geometry and H has S orbital. 4S orbitals of H overlap with four sp3 orbitals of C to produce CH4, a tetrahedral compound.