How many carbon atoms are present in 2.8 g of C2H4?

• A. 2.4 × 10^{23}
• B. 1.2 × 10^{23}
• C. 6.0 × 10^{22}
• D. 8.4 × 10^{22}

Answer: (B)

Verified step by step guidance

1. Determine the molar mass of ethylene (C\_2H\_4) by adding the atomic masses of its atoms: 2 carbon atoms and 4 hydrogen atoms. Use the atomic masses approximately as 12.0 g/mol for carbon and 1.0 g/mol for hydrogen. The molar mass is calculated as \(\text{Molar mass} = 2 \times 12.0 + 4 \times 1.0\) g/mol.
2. Calculate the number of moles of C\_2H\_4 in 2.8 g by using the formula \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\), where the mass is 2.8 g and the molar mass is from step 1.
3. Find the total number of molecules of C\_2H\_4 by multiplying the number of moles by Avogadro's number, \$6.022 \times 10^{23}\( molecules/mol, using the formula \)\text{molecules} = \text{moles} \times 6.022 \times 10^{23}$.
4. Since each molecule of C\_2H\_4 contains 2 carbon atoms, calculate the total number of carbon atoms by multiplying the number of molecules by 2: \(\text{carbon atoms} = 2 \times \text{molecules}\).
5. Express the final answer in scientific notation to match the format of the given options.