Question

Consider a mixture of three different gases: 1.20 g of argon (molecular mass = 39.948 g/mol), 2.60 g of neon (molecular mass = 20.180 g/mol), and 3.20 g of helium (molecular mass = 4.0026 g/mol). For this mixture, determine the percentage of the total number of atoms that corresponds to each of the components.

I honestly don't know if it's my calculator or just me. Please help.

Answer 1

we have the formula

Number of moles=mass/molecular mass

so for argon

Number of moles=1.2g/39.948g/mol=0.030039 moles

for neon

number of moles=2.6g/20.180=0.128840moles

for helium

number of moles=3.2g/4.0026=0.799480 moles

so total number of moles are=0.958359 moles

and total number of atoms are=0.958359*6.022*10²³=5.771*10²³atoms

the percentage of atoms argon makes =(0.030039/.958359)*100=3.13%

the percentage of atoms neon makes=.12884/.958359)*100=13.44%

the percentage of atoms helium makes=(.799480/.958359)*100=83.42%