Question

How many electrons are present in 1.6 gm of methane?

Answer 1

First you must find the no. on moles in 1.6g of ch4.      
now ch4=C+h4=12+(1.008x4)=16.032 or 16 approx

moles=1.6/16=0.1

No. of electrons=no. atoms

e.g  ,no of moles x 6.022x10^23

=0.1x 6.022x10^23

=>6.022 x 10^23(approx)

Answer 2

mole = given weight/molecular weight 
 molecular weight of CH₄ = 16g/mol
given weight = 1.6 g

no of mole = 1.6/16 = 0.1 
no of molecule in 0.1mole of CH₄ = 0.1 ×6.023 × 10²³
                                                        =6.023×10²²
now,
   no of electrons = 10 × no of molecules
                              =10×6.023×10²²
                              =6.023 ×10²³