Question

(a) Draw the structures of the following molecules:
(i) $N_2{O}_5$ (ii) $HCl{O}_4$
(b) Explain the following observations :
(i) $H_{2}S$ is more acidic than $H_{2}O$.
(ii) Fluorine does not exhibit any positive oxidation state.
(iii) Helium forms no real chemical compound.

Answer 1

(i) The S-H bond is weaker than the $O-H$ bond, meaning that $H_{2}S$ more easily donates a proton and is, therefore, more acidic. Water is amphoteric; it can act both as a proton donor (acid property) and as a proton acceptor (base property).

(ii) Fluorine has the highest electronegativity on any of the elements, in order for it to get a positive charge, you would need another element with even higher electronegativity, which doesn't exist.

(iii) Because it has 2 electrons which fill up its electron shell, making it unreactive and stable.