The ratio of molecules present in 6.6 g of `CO_2` and 3.2 g of `SO_2` is:

Explanation

To find the ratio of molecules present in 6.6 g of CO₂ and 3.2 g of SO₂, we will follow these steps:

### Step 1: Calculate the molecular mass of CO₂
- The molecular mass of CO₂ is calculated as follows:
- Carbon (C) has an atomic mass of 12 g/mol.
- Oxygen (O) has an atomic mass of 16 g/mol, and there are 2 oxygen atoms in CO₂.

\[ \text{Molecular mass of CO₂} = 12 + (2 \times 16) = 12 + 32 = 44 \text{ g/mol} \]

### Step 2: Calculate the number of moles of CO₂ in 6.6 g
- Use the formula for moles:

\[ \text{Moles of CO₂} = \frac{\text{Given mass}}{\text{Molecular mass}} = \frac{6.6 \text{ g}}{44 \text{ g/mol}} = 0.15 \text{ moles} \]

### Step 3: Calculate the number of molecules of CO₂
- Use Avogadro's number (6.022 × 10²³ molecules/mol):

\[ \text{Number of molecules of CO₂} = 0.15 \text{ moles} \times 6.022 \times 10^{23} \text{ molecules/mol} \approx 0.9033 \times 10^{23} \text{ molecules} \]

### Step 4: Calculate the molecular mass of SO₂
- The molecular mass of SO₂ is calculated as follows:
- Sulfur (S) has an atomic mass of 32 g/mol.
- Oxygen (O) has an atomic mass of 16 g/mol, and there are 2 oxygen atoms in SO₂.

\[ \text{Molecular mass of SO₂} = 32 + (2 \times 16) = 32 + 32 = 64 \text{ g/mol} \]

### Step 5: Calculate the number of moles of SO₂ in 3.2 g
- Use the formula for moles:

\[ \text{Moles of SO₂} = \frac{\text{Given mass}}{\text{Molecular mass}} = \frac{3.2 \text{ g}}{64 \text{ g/mol}} = 0.05 \text{ moles} \]

### Step 6: Calculate the number of molecules of SO₂
- Use Avogadro's number:

\[ \text{Number of molecules of SO₂} = 0.05 \text{ moles} \times 6.022 \times 10^{23} \text{ molecules/mol} \approx 0.3011 \times 10^{23} \text{ molecules} \]

### Step 7: Calculate the ratio of molecules of CO₂ to SO₂
- The ratio is given by:

\[ \text{Ratio} = \frac{\text{Number of molecules of CO₂}}{\text{Number of molecules of SO₂}} = \frac{0.9033 \times 10^{23}}{0.3011 \times 10^{23}} \approx 3 \]

### Final Answer:
The ratio of molecules present in 6.6 g of CO₂ and 3.2 g of SO₂ is approximately **3:1**.

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