How many grams of aspartame (C14H18N2O5), also known as Nutrasweet, contain 1.98*1021molecules of aspartame?

0.97 grams

Explanation:

number of molecules=no of moles * Avogadros number

so

number of moles=nu. of molecules : 6.02*10power23 = 1.98*10power21 : 6.02*10p23=0.0033 mol

mass=nu. of moles * molar mass

molar mass of aspartame=

(14*12) + 18 + (2 * 14.0067n) + (5*16) = 294.0134 u

mass = 0.0033 * 294.0134 = 0.97 gram