Which of the following contains same number of carbon atoms as are in 6.0 g of carbon (C – 12)?

The correct option is 8.0 g Methane.

To understand why this is the correct answer, let us break down the problem into simple steps by calculating the number of moles of carbon atoms in each case.

Step 1: Calculate the moles of carbon atoms in 6.0 g of carbon (C-12)
The molar mass of carbon (C-12) is 12 g/mol.
Using the formula for the number of moles:
$$\text{Moles of Carbon (C)}=\frac{\text{Given Mass}}{\text{Molar Mass}}$$
Substituting the given values:
$$\text{Moles of Carbon (C)}=\frac{6.0\text{ g}}{12\text{ g/mol}}=0.5\text{ mol}$$
Thus, the reference sample contains 0.5 moles of carbon atoms.

Step 2: Analyze the correct option (8.0 g Methane)
Methane has the chemical formula CH₄.
First, calculate the molar mass of methane (CH₄):
$$\text{Molar mass of }{\text{CH}}_4=12\text{ (for C)}+4\times 1\text{ (for H)}=16\text{ g/mol}$$
Now, find the number of moles of methane in 8.0 g:
$$\text{Moles of }{\text{CH}}_4=\frac{8.0\text{ g}}{16\text{ g/mol}}=0.5\text{ mol}$$
Each molecule of methane (CH₄) contains exactly 1 atom of carbon. Therefore, 1 mole of methane contains 1 mole of carbon atoms.
$$\text{Moles of Carbon atoms in 8.0 g Methane}=0.5\text{ mol }\times 1=0.5\text{ mol}$$
Since the number of moles of carbon atoms in 8.0 g of methane (0.5 mol) is equal to that in 6.0 g of carbon (0.5 mol), they contain the same number of carbon atoms.