helium was required to fill the balloon? Find the molar mass of 6.24 g of an unknown gas that occupies 2.5 Lat 18.3^circ C and 100.5 kPa.

Here's how to solve this problem using the Ideal Gas Law:<br /><br />**1. Convert units to standard SI units:**<br /><br />* **Temperature:** Convert Celsius to Kelvin: 18.3°C + 273.15 = 291.45 K<br />* **Pressure:** Convert kPa to Pa: 100.5 kPa * 1000 Pa/kPa = 100500 Pa<br />* **Volume:** 2.5 L is already in a suitable unit (we'll convert to m³ later as needed).<br /><br />**2. Use the Ideal Gas Law:**<br /><br />The Ideal Gas Law is PV = nRT, where:<br /><br />* P = pressure (Pa)<br />* V = volume (m³)<br />* n = number of moles<br />* R = ideal gas constant (8.314 J/(mol·K))<br />* T = temperature (K)<br /><br />**3. Rearrange the Ideal Gas Law to solve for 'n' (number of moles):**<br /><br />n = PV / RT<br /><br />**4. Convert volume from Liters to cubic meters:**<br /><br />2.5 L * (1 m³/1000 L) = 0.0025 m³<br /><br />**5. Plug in the values and solve for 'n':**<br /><br />n = (100500 Pa * 0.0025 m³) / (8.314 J/(mol·K) * 291.45 K) <br />n ≈ 0.104 moles<br /><br />**6. Calculate the molar mass:**<br /><br />Molar mass (M) = mass (m) / number of moles (n)<br /><br />M = 6.24 g / 0.104 moles<br />M ≈ 60 g/mol<br /><br />**Answer:** The molar mass of the unknown gas is approximately 60 g/mol.<br />