[741]

I found a link (a book extract) showing speed of sound in various gas mixtures.

It shows "3% H₂0 in N₂" as hving a molecular weight of 26.12.

My attempt to verify that number is:

0.97*28 + 0.03*18 = 27.7

Where am I going wrong?

Here is the link
https://books.google.co.uk/books?id=0YDal4Lj59kC&pg=PA246&lpg=PA246&dq=helium+velocity+purity+moisture+sound&source=bl&ots=NZRba6wRWk&sig=I_dcgz6g6qmsUFWH0KaJbssVniE&hl=en&sa=X&ved=0ahUKEwjolZTLtqjcAhWUTcAKHTCJBVQ4ChDoAQhJMAY#v=onepage&q=helium%20velocity%20purity%20moisture%20sound&f=false

[mjc123]

You are right. There must be an error in the book.

[741]

Thanks for checking it for me.