In experiment 1, a sample of propane gas occupies 75.0 mL at constant temperature. If the initial pressure was 1.20 atm at 100.0 mL, what would be the pressure of the propane gas at 75.0 mL?

• A. 1.20 atm
• B. 1.00 atm
• C. 1.60 atm
• D. 0.90 atm

Answer: (C)

Verified step by step guidance

1. Identify the gas law that relates pressure and volume at constant temperature, which is Boyle's Law. Boyle's Law states that \(P_1 V_1 = P_2 V_2\), where \(P\) is pressure and \(V\) is volume.
2. Write down the known values from the problem: initial pressure \(P_1 = 1.20\) atm, initial volume \(V_1 = 100.0\) mL, and final volume \(V_2 = 75.0\) mL. The final pressure \(P_2\) is what we need to find.
3. Rearrange Boyle's Law to solve for the unknown pressure \(P_2\): \(P_2 = \frac{P_1 V_1}{V_2}\).
4. Substitute the known values into the equation: \(P_2 = \frac{1.20 \text{ atm} \times 100.0 \text{ mL}}{75.0 \text{ mL}}\).
5. Calculate the value of \(P_2\) to find the new pressure of the propane gas at 75.0 mL.