problem solving

40. Write Lewis structures for the following:

(a) O2

(b) H2CO

(c) AsF3

(d) ClNO

(e) SiCl4

(f) H3O +

(g) NH4 +

(h) BF4 –

(i) HCCH

(j) ClCN

(k) C2 2+

51. How much heat is required to convert 422 g of liquid H2O at 23.5 °C into steam at 150 °C?