A coal-fired power station is used to generate electricity - VCE - SSCE Chemistry - Question 2 - 2022 - Paper 1

To calculate the pressure of the CO₂ gas in the tank, we can use the Ideal Gas Law, which is given by:

$PV = nRT$

Where:

• $P$ is the pressure in kilopascals (kPa)
• $V$ is the volume in liters (L)
• $n$ is the number of moles of gas
• $R$ is the ideal gas constant, approximately 8.314 L·kPa/(K·mol)
• $T$ is the temperature in Kelvin (K)

Step 1: Convert the temperature to Kelvin. The temperature is given as 28.0 °C. To convert to Kelvin: $T = 28.0 + 273.15 = 301.15 \, K$

Step 2: Substitute variables into the ideal gas law. Rearranging the Ideal Gas Law to find $P$ gives: $P = \frac{nRT}{V}$ Substituting in the known values:

• $n = 5.17 × 10^4 \, mol$
• $R = 8.314 \, L·kPa/(K·mol)$
• $V = 20000.0 \, L$ Thus, $P = \frac{(5.17 × 10^4)(8.314)(301.15)}{20000.0}$

Step 3: Perform the calculation.

Simplifying this gives: $P = \frac{(5.17 × 10^4)(8.314)(301.15)}{20000.0} \approx 64.2 \, kPa$

Therefore, the pressure in the tank is approximately 64.2 kPa.