The number of moles of nitrogen present in one litre of air containing 13% nitrogen by volume, under standard condition, is:

Options

A. 5.8 x `10^(-3)`
B. 4.91 x `10^(-2)`
C. 7.84 x `10^(-3)`
D. None

Explanation

To find the number of moles of nitrogen present in one liter of air containing 13% nitrogen by volume under standard conditions, we can follow these steps:

### Step 1: Determine the volume of nitrogen in 1 liter of air.
Since the air contains 13% nitrogen by volume, we can calculate the volume of nitrogen in 1 liter of air as follows:

\[ \text{Volume of Nitrogen} = \frac{13}{100} \times 1 \text{ L} = 0.13 \text{ L} \]

### Step 2: Use the ideal gas law to find the number of moles.
At standard temperature and pressure (STP), one mole of an ideal gas occupies 22.4 liters. We can use this information to find the number of moles of nitrogen in 0.13 liters:

\[ \text{Number of moles of Nitrogen} = \frac{\text{Volume of Nitrogen}}{\text{Volume of 1 mole at STP}} = \frac{0.13 \text{ L}}{22.4 \text{ L/mol}} \]

### Step 3: Calculate the number of moles.
Now we can perform the calculation:

\[ \text{Number of moles of Nitrogen} = \frac{0.13}{22.4} \approx 0.00580 \text{ moles} \]

### Step 4: Express the result in scientific notation.
To express 0.00580 in scientific notation:

\[ 0.00580 = 5.80 \times 10^{-3} \text{ moles} \]

### Final Answer:
The number of moles of nitrogen present in one liter of air containing 13% nitrogen by volume under standard conditions is approximately \( 5.80 \times 10^{-3} \) moles.

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