The number of moles of carbon dioxide which contain 8 g of oxygen is

Options

A. 0.5 mole
B. 0.20 mole
C. 0.40 mole
D. 0.25 mole

Explanation

To find the number of moles of carbon dioxide (CO₂) that contain 8 g of oxygen, we can follow these steps:

### Step 1: Determine the molar mass of CO₂
The molecular formula of carbon dioxide is CO₂, which consists of one carbon atom and two oxygen atoms. The molar mass can be calculated as follows:
- Molar mass of Carbon (C) = 12 g/mol
- Molar mass of Oxygen (O) = 16 g/mol
- Therefore, the molar mass of CO₂ = 12 g/mol (C) + 2 × 16 g/mol (O) = 12 + 32 = 44 g/mol.

### Step 2: Calculate the moles of oxygen in 8 g
To find out how many moles of oxygen are in 8 g, we use the formula:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]
The molar mass of oxygen (O₂) is 32 g/mol (since there are two oxygen atoms in CO₂). Therefore:
\[ \text{Number of moles of O} = \frac{8 \text{ g}}{32 \text{ g/mol}} = 0.25 \text{ moles of O} \]

### Step 3: Relate moles of oxygen to moles of CO₂
From the molecular formula CO₂, we know that one mole of CO₂ contains 2 moles of oxygen. Therefore, to find the number of moles of CO₂ that correspond to 0.25 moles of oxygen, we can set up the following relationship:
\[ \text{Moles of CO₂} = \frac{\text{Moles of O}}{2} = \frac{0.25}{2} = 0.125 \text{ moles of CO₂} \]

### Final Answer
Thus, the number of moles of carbon dioxide (CO₂) that contain 8 g of oxygen is **0.125 moles**.

---