Question

calculate the number of atoms of o in 10.0 g of c₂h₆o₂.

Explanation:

Step1: Calculate molar mass of \( C_2H_6O_2 \)

Molar mass of \( C \): \( 12.01\ g/mol \), \( H \): \( 1.008\ g/mol \), \( O \): \( 16.00\ g/mol \)
Molar mass \( = 2\times12.01 + 6\times1.008 + 2\times16.00 = 62.076\ g/mol \)

Step2: Find moles of \( C_2H_6O_2 \)

Moles \( = \frac{mass}{molar\ mass} = \frac{10.0\ g}{62.076\ g/mol} \approx 0.1611\ mol \)

Step3: Moles of O atoms

1 mole \( C_2H_6O_2 \) has 2 moles O, so moles of O \( = 0.1611\ mol \times 2 = 0.3222\ mol \)

Step4: Number of O atoms (Avogadro's number \( N_A = 6.022\times10^{23}\ mol^{-1} \))

Atoms \( = 0.3222\ mol \times 6.022\times10^{23}\ mol^{-1} \approx 1.94\times10^{23} \)

Answer:

\( \approx 1.94\times10^{23} \) atoms