Molar mass of C7H5N3O6 =12×7+5+14×3+16×6 =227gm Given mass of C7H5N3O6=681gm ∴ Moles of C7H5N3O6=
681
227
=3 In one molecule of C7H5N3O6,3N atoms present. ∴ In 1 mole C7H5N3O6,3 moles of N atoms presents. ∴ In 3 moles of C7H5N3O6,3×3=9 moles of N atoms presents. We know, 1 mole of N atoms =6.02×1023N atoms. ∴9 moles of N atoms =9×6.02×1023=54.18×1023=5418×1021