Using PV = nRT, calculate the pressure for n = 0.200 mol in V = 5.00 L at T = 298 K.

Using PV = nRT, calculate the pressure for n = 0.200 mol in V = 5.00 L at T = 298 K.

• A. 0.50 atm
• B. 0.98 atm
• C. 2.00 atm
• D. 6.00 atm

Answer: (B)

P = nRT / V. This shows how pressure depends on the amount of gas, temperature, and volume. Plug in the values with R = 0.082057 L·atm/(mol·K): P = (0.200 mol)(0.082057 L·atm/(mol·K))(298 K) / (5.00 L) Compute: 0.200 × 0.082057 × 298 ≈ 4.8906 Then 4.8906 / 5.00 ≈ 0.978 atm So the pressure is about 0.98 atm (3 significant figures). This aligns with the intuition that a small amount of gas at room temperature in a moderate volume yields near 1 atm. The other options would require noticeably different n, T, or V to produce those pressures.

P = nRT / V. This shows how pressure depends on the amount of gas, temperature, and volume.

Plug in the values with R = 0.082057 L·atm/(mol·K):

P = (0.200 mol)(0.082057 L·atm/(mol·K))(298 K) / (5.00 L)

Compute: 0.200 × 0.082057 × 298 ≈ 4.8906

Then 4.8906 / 5.00 ≈ 0.978 atm

So the pressure is about 0.98 atm (3 significant figures). This aligns with the intuition that a small amount of gas at room temperature in a moderate volume yields near 1 atm. The other options would require noticeably different n, T, or V to produce those pressures.