1)

15 moles of Ne
10 moles of N2
Enter the mass percent of Ne
MM[Ne]=20.18 g/mol, MM[N2]=28.01 g/mol

mass Ne = 15 moles x molar mass Ne = ??

mass N2 = 10 moles x molar mass N2 = ??
total mass = mass Ne + mass N2.

%Ne = (mass Ne/total mass)*100 = ??
%N2 = (mass N2/total mass)*100 = ??