Out of the following hydrides of group 16 elements, which will have : (i) H2S (ii) H2O (iii) H2 Te (a) lowest boiling point (b) highest bond angle (c) highest electropositive hydrogen.
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Please find the solution to the asked query:
i) Water makes strongest hydrogen bonds, so it has highest boiling point.
in hydrogen sulphide H2S, even though there are intermolecular forces of attraction between atoms, hydrogen bonding is not present. Hence the H2S requires less energy to break the bonds with low boiling point of 213 K.
ii)because of decreasing electronegativity of group 16 elements on going down the group. 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. On going down the group, electronegativity of central atom decreases, thus reducing its tendency to attract shared pair of electrons towards itself. So lone pair-bond pair repulsions become more efficient as against bond pair-bond pair repulsions thus reducing the bond angle.
Hence H2O has the maximum bond angle.
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