Find the no. of moles of `O_2` present in 1.20x`10^22` molecules of oxygen gas?

Options

A. 0.0199
B. 0.2
C. 0.1
D. 1.09

Explanation

To find the number of moles of \( O_2 \) present in \( 1.20 \times 10^{22} \) molecules of oxygen gas, we can follow these steps:

### Step 1: Understand Avogadro's Number
Avogadro's number (\( N_A \)) is the number of molecules in one mole of a substance. It is approximately \( 6.02 \times 10^{23} \) molecules/mole.

### Step 2: Set Up the Conversion
We need to convert the number of molecules into moles using the formula:
\[ \text{Number of moles} = \frac{\text{Number of molecules}}{N_A} \]
In this case, the number of molecules is \( 1.20 \times 10^{22} \).

### Step 3: Substitute the Values
Substituting the values into the formula gives us:
\[ \text{Number of moles} = \frac{1.20 \times 10^{22}}{6.02 \times 10^{23}} \]

### Step 4: Perform the Calculation
Now, we perform the division:
\[ \text{Number of moles} = \frac{1.20}{6.02} \times \frac{10^{22}}{10^{23}} = \frac{1.20}{6.02} \times 10^{-1} \]
Calculating \( \frac{1.20}{6.02} \) gives approximately \( 0.199 \).

Thus,
\[ \text{Number of moles} \approx 0.199 \times 10^{-1} = 0.0199 \]

### Step 5: Final Answer
The number of moles of \( O_2 \) in \( 1.20 \times 10^{22} \) molecules is approximately:
\[ \text{Number of moles} \approx 0.0199 \]