Question

Alveoli are tiny sacs in the lungs whose average diameter is 5×10−10m. An oxygen molecule is trapped in a sac. The uncertainty in the velocity of oxygen molecule within a sac is​

Answer 1

molar mass of oxygen gas = 32g/mol

so, mass of one molecule of oxygen gas = 32 × 10^-3/(6.023 × 10²³)

= 5.312 × 10^-26 Kg

given, uncertainty in position, ∆x = 5 × 10^-10m

using formula,

$\Delta x\Delta V=\frac{h}{4\pi m}$

or, $\Delta V=\frac{h}{4\pi m\Delta x}$

= 6.63 × 10^-34/(4 × 3.14 × 5.312 × 10^-26 × 5 × 10^-10)

≈ 2 m/s

hence, uncertainty in the velocity of oxygen molecule within a sac is 2 m/s