Physics problem (Matter)

用戶199399

2009-03-01 7:25 pm

1. Given that density of water = 1000 kgm^-3 and molar mass of water
= 0.018 kg. Find the average separation between water molecules.
(Avogadro constant = 6.02*10^23 mol^-1)

2. One mole of gas molecules at s.t.p (273 K and 1 a.t.m.) has a volume of 0.0224 m^-3. Find the average separation between gas molecules.

回答 (1)

Prof. Physics

2009-03-01 7:34 pm

✔ 最佳答案

1. One mole of water has the mass of 0.018 kg. It has 6.02 X 10^23 water molecules.

So, one mole of water has the volume

= Mass / density

= 0.018 / 1000

= 1.8 X 10^-5 m^3

So, in average, one water molecule has the volume

= (1.8 X 10^-5) / (6.02 X 10^23)

= 2.99 X 10^-29 m^3

So, the average separation between water molecules

= (2.99 X 10^-29)^(1/3)

= 3.10 X 10^-10 m

2. Average volume occupied by one gas molecule

= (0.0224) / (6.02 X 10^23)

= 3.72 X 10^-26 m^3

So, average separation between gas molecules

= (3.72 X 10^-26)^(1/3)

= 3.34 X 10^-9 m

參考: Physics king

👍 0 👎 0