The number of N atoms in 681g of C _ 7 H _ 5 N _ 3 O _ 6 is x × 10...

Given mass of compounds $= 681g$

Molar mass of ${C}_{7}{H}_{5}{N}_{3}{O}_{6} = 12 \times 7 + 5 \times 1 + 14 \times 3 + 6 \times 16$

$= 84 + 5 + 42 + 96$

$= 227$

Number of moles of compound $= \dfrac{681}{227} = 3$ moles

Number of moles of $N = 3 \times$number of moles of compound

$= 3 \times 3 = 9$ moles

Number of atoms of N $= 9 \times 6 . 02 \times {10}^{23}$

$= 5418 \times {10}^{21}$

So $x = 5418$