What is the mass of #3.8*10^24# atoms of argon?

1 Answer
Oct 17, 2016

Answer:

#3.8xx10^24# argon atoms have a mass of approx. #250*g#.

Explanation:

#6.022xx10^23# argon atoms have a mass of #39.95*g#. How do I know this? Well, #6.022xx10^23# is #"Avogadro's number"#, and the Periodic Table lists the mass of #"Avogadro's number of each atom"#.

And thus we calculate the product:

#(3.8xx10^24" argon atoms")/(6.022xx10^23" argon atoms mol"^-1)xx39.95*g*mol^-1# #=# #??g#

Argon is often used in the laboratory to provide a protective blanket of inert gas for reactions with air and water sensitive reagents. Why should argon be unreactive towards the reagents?