在常溫常壓下，
假設該粒乾燥的分子含標準成份，即78%N2、21%O2等
根據wikipedia，乾燥空氣的摩爾質量為28.9634 g/mol。
以此計算，
求一粒空氣分子的質量,
=(28.9634E-3)*(6.02E-23)
=1.74E-24 kg
另外，一粒質子或中子質量約為1u
即1.66E-27 kg
兩者相差約1050倍，相差並不合理
是否計算錯誤?或提供標準的理論值，謝謝。
一粒空氣分子的質量是多少?
2010-01-03 8:41 am
回答 (3)
2010-01-03 9:35 am
✔ 最佳答案
You have made a mistake in your calculation.The mass of an air molecules, from the molar mass of air, is
= 28.96/(6.02x10^23) g = 4.8 x 10^-23 g = 4.8 x 10^-26 kg
Since the molar mass indicates the number of nucleons (protons or neutrons) in a molecule, the mass of an air molecule, assuming neutron and proton are of the same mass, is
= 28.96 x (1.66 x 10^-27) kg = 4.8 x 10^-26 kg
The two results are the same
You have compared the mass of a proton and the mass of an air molecule, which contains, on average 28.96 protons/neutrons. You can't expect to have the same result.
2010-01-12 8:34 am
看了你的意見我更明白了.
唔該曬=]
唔該曬=]
2010-01-03 7:14 pm
同學 , 你搞錯左d數學上既野
求一粒空氣分子的質量,
=(28.9634E-3)*(6.02E-23) <----
(28.9634E-3)乘(6.02E^-23)
你一係
(28.9634E-3)乘(6.02E^23)^-1
一係
(28.9634E-3)除(6.02E^23)
你既情況好似計: 100 除60咁
你寫成 100x6x10^-1 = 60 , 係錯既
前面既6都要倒數嫁
求一粒空氣分子的質量,
=(28.9634E-3)*(6.02E-23) <----
(28.9634E-3)乘(6.02E^-23)
你一係
(28.9634E-3)乘(6.02E^23)^-1
一係
(28.9634E-3)除(6.02E^23)
你既情況好似計: 100 除60咁
你寫成 100x6x10^-1 = 60 , 係錯既
前面既6都要倒數嫁
收錄日期: 2021-04-29 17:33:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100103000051KK00075