Question

What is the mass of 5 mole of ammonia . Calculate the number of NH₃ molecules, nitrogen atom and hydrogen atoms in it..

Answer 1

Molar mass of NH_3

$\\ \sf\longmapsto 14u+3(1u)$

$\\ \sf\longmapsto 14u+3u$

$\\ \sf\longmapsto 17g/mol$

We know.

No of moles=Given mass/Molar mass

$\\ \sf\longmapsto Given\;Mass=17(5)$

$\\ \sf\longmapsto Given \:Mass\:of\:NH_3=85g$

Now

Lets write the balanced equation

$\\ \sf\longmapsto N_2+3H_2=2NH_3$

• There is 2moles of Ammonia
• 3moles of H_2
• 1mole of N_2

Now

$\boxed{\sf No\:of\:Molecules =No\:of\;moles\times Avagadro\:no}$

For Hydrogen

$\\ \sf\longmapsto 3\times 6.023\times 10^{23}$

$\\ \sf\longmapsto 18.069\times 10^{23}$

$\\ \sf\longmapsto 1.8\times 10^{22}molecules$

For Ammonia

$\\ \sf\longmapsto 2\times 6.023\times 10^{23}$

$\\ \sf\longmapsto 12.046\times 10^{23}$

$\\ \sf\longmapsto 1.2\times 10^{22}molecules$

For Nitrogen

$\\ \sf\longmapsto 1\times 6.023\times 10^{23}$

$\\ \sf\longmapsto 6.023\times 10^{23}molecules$