(a) How many particles are represented by 0.25 mole of an element?
(b)Out of 4g of methane and 11 g of `CO_2` , Does they contain equal no. of molecules `(1 N _A=6.022xx10^(23)` molecules )

Explanation

1.0mole of the element represents particles `=6.022xx10^(23)`
0.25mole of the elements represents particles =`=((6.022xx10^23)xx(0.25"mol"))/((1.0"mol"))`
`=1.505xx10^(23)"particles"`
(b) 4g of methane `(CH_(4))` represebts moles `=((1"mol")xx(4g))/((16g))=0.25"mol"`
`11"g of "CO_(2)"represents moles"=((1"mol")xx(11g))/((44g))=0.25"mol"`
Since both `CH_(4) and CO_(2)` haave same number of moles (0.25moles), they have also same number of molecules.