Question #0a3ea

1 Answer
Sep 8, 2017

Answer:

#1.51*10^24# atoms

Explanation:

1 mole of a molecule contains Avogadro's number of molecules.

Where,
#"Avogadro's number "= 6.02*10^23#

So one mole of #CH_4# contains #6.02*10^23# molecules of #CH_4#

Half a mole would contain half the amount that a mole contain,

In 0.5 mole of #CH_4#, there is #(6.02*10^23)/2=3.01*10^23#

But one molecule of #CH_4# contains 5 atoms (1 atom of carbon and 4 atoms of Hydrogen).

So number of atoms in 0.5 mole of #CH_4# is equal to number of molecules in 0.5 mol multiplied by 5.
#"number of atoms in 0.5 mole of CH_4"= "5⋅number of molecules in 0.5 mol" = 5*3.01*10^23=15.05*10^23=1.505*10^24≈1.51*10^24#

Hope that this will help. :)