Solution :
We know, molecular mass of NH₃ is , M = 17 g/mol .
Number of moles of NH₃ in 7.2 × 10²⁴ are :
[tex]n = \dfrac{7.2 \times 10^{24}}{6.022 \times 10^{23}}\\\\n = 11.96\ moles[/tex]
So, mass of NH₃ present in 11.96 moles is :
m = 11.96 × 17 gram
m = 203.32 gram
Hence, this is the required solution.
