(i) Show that 100 g of water and 100 g of carbon dioxide are not equal in number of moles. Molecular masses of water and carbon dioxide are 18 u and 44 u respectively.
(iii) Calculate the number of molecules present in 100 g of both water and carbon dioxide.
(i)Number of moles = Given mass / molar mass
Number of moles of water = 100/18 = 5.55 moles
Number of moles of $C{{O}{2}}$ = 100/44 = 2.27 moles
Hence , 100 g of water and 100 g of carbon dioxide are not equal in number of moles.
(ii) 1 mole = 6.022 x ${10}^{23}$ molecules.
5.5 moles of water = 5.5 x 6.022 x ${10}^{23}$ = 3.31 x ${10}^{24}$ molecules.
2.27 moles of $C{{O}{2}}$ = 2.27 x 6.022 x ${10}^{23}$ = 1.36 x ${10}^{24}$ molecules.