Question

The order of magnitude of the number of nitrogen molecules in air bubble of diameter 2mm under ordinary condition is

• A. ${10}^5$
• B. ${10}^9$
• C. ${10}^{13}$
• D. ${10}^{17}$

Answer 1

The correct option is D ${10}^{17}$

Molar volume = $22400c{m}^3$

Bubble volume - $\frac{4}{3}\pi \frac{d^3}{8}$ = $\frac{4}{3}\pi {10}^{-9}$

No. of molecules = $\frac{6\times {10}^{23}\times 4\pi {10}^{-9}}{22400\times {10}^{-6}\times 3}$ $\approx$ ${10}^{17}$