# Question 13068

Jan 1, 2017

The volume occupied by an oxygen molecule at STP is ${\text{37.71 nm}}^{3}$.

#### Explanation:

STP is defined as a temperature of 0 °C and a pressure of 1 bar.

At STP, 1 mol of oxygen occupies ${\text{22.71 dm}}^{3}$.

The average volume occupied by a molecule is

V = (22.71 color(white)(l) "dm"^3)/(6.022 × 10^23 color(white)(l)"molecules") = 3.771 × 10^"-23"color(white)(l) "dm"^3"/molecule"

 3.771 × 10^"-23" color(red)(cancel(color(black)("dm"^3))) × ((1 color(red)(cancel(color(black)("m"))))/(1 0color(red)(cancel(color(black)("dm")))))^3 × ((10^9color(white)(l) "nm")/(1 color(red)(cancel(color(black)("m")))))^3 = "37.71 nm"^3#

An oxygen molecule is so small that 99.9 % of this volume is empty space.