Q.

The number of water molecules is maximum in           [2015]

1 1.8 gram of water  
2 18 gram of water  
3 18 moles of water  
4 18 molecules of water.  

Ans.

(3)

1.8 gram of water =6.023×102318×1.8

                              =6.023×1022 molecules

18 gram of water =6.023×1023 molecules

18 moles of water =18×6.023×1023 molecules