How many moles of He are contained in a 5L canister at 100KPa and 25oC. Take R = 8.314 L/mol K.

To solve this problem, we can use the ideal gas law equation, which is PV = nRT.

Here's the step-by-step solution:

1. Convert the temperature to Kelvin. The formula to convert Celsius to Kelvin is K = °C + 273.15. So, 25°C = 25 + 273.15 = 298.15 K.

2. Convert the pressure to Pascals. The formula to convert kilopascals to pascals is 1 kPa = 1000 Pa. So, 100 kPa = 100,000 Pa.

3. Substitute the given values into the ideal gas law equation. We have P = 100,000 Pa, V = 5 L, R = 8.314 L/mol K, and T = 298.15 K. We're solving for n (the number of moles), so the equation becomes 100,000 * 5 = n * 8.314 * 298.15.

4. Solve for n. Divide both sides of the equation by 8.314 * 298.15 to isolate n. n = (100,000 * 5) / (8.314 * 298.15) = 2.01 moles.

So, there are approximately 2.01 moles of He in the 5L canister at the given conditions.