What do the following abbreviations stand for ?
(i) `O` , (ii) `2O` , (iii) `O_(2)` , (iv) `3O_(2)`

The abbreviation B.O.D. stands for

Which of the following are Lewis acids ? (i) H_2O , (ii) BF_3 , (iii) H^+ , (iv) NH_4^+

Write Lewis dot symbols for the following atoms and ions : (i) O (ii) O^(2-) (iii) Mg^(2+) (iv) P^(3-) (v) Br

Which of the following oxides are amphoteric? (i) Tl_(2)O (ii) Al_(2)O_(3) (iii) Ga_(2)O_(3) (iv) In_(2)O_(3)

Classify the following into elements and compounds: (I) H_(2)O (ii) He (iii) Cl_(2) (iv) CO

What is the nature of the following oxides : (i) CO (ii) Al_(2)O_(3) (iii) CO_(2) (iv) CaO (v) SO_(3) ?

Complete the following reactions : (i) O_2^(2-) + H_2O to (ii) O_2^(-) + H_2O to

Name the following compounds : Oxides of sulphur : (i) S_2 O (ii) S_2 O_3 (iii) SO_4 (iv) S_2 O_7 . (b) Oxyacids of sulphur : (i) H_2 SO_2 (ii) H_2 SO_3 (iii) H_2 S_2 O_4 (iv) H_2 S_2 O_2 (v) H_2 S_2 O_5 . (c) Sulphuric acid : (i) H_2 S_2 O_3 (ii) H_2 S_2 O_7 (d) Thionic acids : (i) H_2 S_2 O_6 (ii) H_2 (S)_n O_6 ( e) Peroxo acids : (i) H_2 SO_5 (ii) H_2 S_2 O_8 .

Complete and balance the following equations : (i) Na + O_(2) to (ii) Na_(2)O + H_(2)O to (iii) Cu + HCl to (iv) Cu^(2+) + Zn to