A volleyball is full of pressurized air. The air temperature is [tex]24.6^{\circ} C[/tex]. The volleyball's absolute pressure is 130.75 kilopascals, and its volume is 5.27 liters. How many moles of air are inside the volleyball?

A. 0.278 mol
B. 3.37 mol
C. 3.59 mol
D. 25.2 mol
E. 28.0 mol



Answer :

To determine the number of moles of air inside the volleyball, we need to use the Ideal Gas Law, which is given by the equation:

[tex]\[ PV = nRT \][/tex]

Where:
- [tex]\( P \)[/tex] is the pressure in pascals (Pa).
- [tex]\( V \)[/tex] is the volume in cubic meters (m³).
- [tex]\( n \)[/tex] is the number of moles.
- [tex]\( R \)[/tex] is the ideal gas constant (8.314 J/(mol·K)).
- [tex]\( T \)[/tex] is the temperature in Kelvin (K).

Let's follow the steps to solve this problem:

1. Convert temperature from Celsius to Kelvin:
The temperature in Kelvin [tex]\( T \)[/tex] is given by:
[tex]\[ T = T_{\text{Celsius}} + 273.15 \][/tex]
Substituting the given temperature:
[tex]\[ T = 24.6 + 273.15 = 297.75 \, K \][/tex]

2. Convert pressure from kilopascals to pascals:
The pressure in pascals [tex]\( P \)[/tex] is:
[tex]\[ P = 130.75 \, \text{kPa} \times 1000 \, \text{Pa/kPa} = 130750 \, \text{Pa} \][/tex]

3. Convert volume from liters to cubic meters:
The volume in cubic meters [tex]\( V \)[/tex] is:
[tex]\[ V = 5.27 \, \text{liters} \times 0.001 \, \text{m}^3/\text{liter} = 0.00527 \, \text{m}^3 \][/tex]

4. Rearrange the ideal gas law to solve for [tex]\( n \)[/tex]:
[tex]\[ n = \frac{PV}{RT} \][/tex]

Now, substitute the known values:
[tex]\[ n = \frac{130750 \, \text{Pa} \times 0.00527 \, \text{m}^3}{8.314 \, \text{J/(mol·K)} \times 297.75 \, \text{K}} \][/tex]

5. Calculate the number of moles [tex]\( n \)[/tex]:
[tex]\[ n \approx 0.28 \, \text{mol} \][/tex]

Thus, the number of moles of air inside the volleyball is approximately 0.28 mol.

So, the correct answer is:

A. 0.278 mol