Respuesta :
The number of moles is given by:
[tex]number of moles = \frac{mass of element/compound}{Molar mass of element/compound}[/tex]
Mass of hydrogen, [tex]H_2[/tex] = [tex]5.85\times 10^{-4} g[/tex] (given)
Molar mass of hydrogen, [tex]H_2[/tex] = [tex]2\times 1 = 2 g/mol[/tex]
Number of moles of hydrogen, [tex]H_2[/tex] = [tex]\frac{5.85\times 10^{-4} g}{2 g/mol} = 2.92\times 10^{-4} mol[/tex]
Reaction between [tex]N_2 and H_2[/tex] to form [tex]NH_3[/tex] is:
[tex]N_2 + 3H_2\rightarrow 2NH_3[/tex]
From the reaction it is clear that 3 moles of hydrogen gives 2 moles of ammonia and 1 mole of nitrogen gives 2 moles of ammonia .
So, [tex]2.92\times 10^{-4} mol[/tex] of [tex]H_2[/tex] gives:
Number of moles of ammonia, [tex]NH_3[/tex] = [tex]\frac{2}{3}\times 2.92\times 10^{-4} = 1.95 \times 10^{-4} mol[/tex]
Since, in one mole of ammonia, [tex]NH_3[/tex] there are [tex]6.022\times 10^{23}[/tex] molecules of ammonia, [tex]NH_3[/tex].
So, number of molecules in [tex]1.95 \times 10^{-4} mol[/tex] of ammonia, [tex]NH_3[/tex] is:
[tex]1.95 \times 10^{-4}\times 6.022\times 10^{23} = 11.74\times 10^{19} molecules[/tex]
Hence, the number of molecules of ammonia produced by [tex]5.85\times 10^{-4} g[/tex] of [tex]H_2[/tex] is [tex]1.174\times 10^{20} molecules[/tex].
