Question

28 select the correct answer. how many atoms of n are in 137.0 grams of n₂o₃? a. 1.085×10²³ b. 1.802×10²³ c. 5.985×10²³ d. 2.171×10²⁴

Explanation:

Step1: Calculate molar mass of N₂O₃

The molar mass of N is 14.01 g/mol and O is 16.00 g/mol. For N₂O₃, $M = 2\times14.01+3\times16.00=76.02$ g/mol.

Step2: Calculate moles of N₂O₃

$n=\frac{m}{M}$, where $m = 137.0$ g and $M = 76.02$ g/mol. So $n=\frac{137.0}{76.02}\approx1.802$ mol.

Step3: Calculate moles of N atoms

In 1 mole of N₂O₃, there are 2 moles of N atoms. So moles of N atoms in 1.802 mol of N₂O₃ is $n_N=2\times1.802 = 3.604$ mol.

Step4: Calculate number of N atoms

Using Avogadro's number $N_A = 6.022\times10^{23}$ atoms/mol, the number of N atoms $N=n_N\times N_A=3.604\times6.022\times10^{23}\approx2.171\times 10^{24}$ atoms.

Answer:

D. $2.171\times 10^{24}$