The number of N atoms in 681 g of C₇H₅N₃O₆ is x * 10²¹. The value of x is___________.

(N_A = 6.02 * 10²³ mol^-1) (Nearest Integer)

Molar mass of C₇H₅N₃O₆ = 12 * 7 + 1 * 5 + 14 * 3 + 16 * 6 = 84 + 42 + 96 = 227 g/mol

Number of moles = $\frac{681}{227}$  = 3 mol

$\therefore$ number of N-atoms

$=3*6.02*10^{23}*3=9*6.02*10^{23}$

$=5418*10^{21}$

$\therefore x=5418$