Question

The number of moles of water present in a spherical water droplets of radius 1.0 cm is:
[Given: density of water in the droplet
$=1.0gc{m}^{-3}$]

• A. $\frac{\pi }{18}$
• B. $\frac{2\pi }{27}$
• C. $24\pi$
• D. $\frac{2\pi }{9}$

Answer 1

The correct option is B $\frac{2\pi }{27}$

$Given:r=1.0cm,d=1.0g/c{m}^{3}d=\frac{M}{V}=1M=V\text{Number of moles}=\frac{\text{mass given}}{\text{molecular mass}}=\frac{\text{volume given}}{\text{molecular mass}}=\frac{\frac{4}{3}\pi r^3}{18}=\frac{2\pi }{27}$