chem mole數 (15分 急)

If 10g of agron contains 2x atoms.what is the number of atoms in 14g of nitrogen gas?
(relative atomic masses:N=14.0 ,Ar=40.0)


The answer is D (8x). ...... (answer)


Denote Avogadro constant = L mol-1

No. of moles of 10 g of Ar = 10/40 = 0.25 mol
No. of atoms in 10 g of Ar = 0.25L atoms
Given that no. of atoms in 10 g of Ar = 2x atoms

Hence, 0.25L = 2x
L = 8x

No. of moles of 14 g of N2 gas = 14/(14 x 2) = 0.5
No. of molecules in 14 g of N2 gas = 0.5L
No. of atoms in 14 g of N2 gas = 0.5L x 2 = L = 8x atoms

( 40g/1mol Ar)=(10g/y molAr)
y=0.25
no. of atom=2x=1/4 mol
x=1/8 mol
and
forN :14g=1mol atom
=8x