Calculating the Initial Volume of Oxygen Gas Sample Using Combined Gas Law

Question:

A sample of oxygen gas initially at 331 K was heated to 385 K. If the volume of the oxygen gas sample at 385 K is 626.9 mL, what was its volume at 331 K?

Answer:

The initial volume of the oxygen gas sample at 331 K was approximately 549.2 mL. To find the initial volume of the oxygen gas sample at 331 K, we can use the combined gas law, which states that the ratio of initial and final volumes of a gas is equal to the ratio of initial and final temperatures, assuming pressure remains constant.

The Combined Gas Law Equation:

(V1 / T1) = (V2 / T2)

Where:

V1 = Initial volume of the gas (unknown)

T1 = Initial temperature in Kelvin (331 K)

V2 = Final volume of the gas (626.9 mL)

T2 = Final temperature in Kelvin (385 K)

Now, we can rearrange the equation to solve for V1:

V1 = (V2 * T1) / T2

V1 = (626.9 mL * 331 K) / 385 K

V1 = 211,208.9 mL K / 385

V1 ≈ 549.2 mL

Therefore, at 331 K, the oxygen gas sample's initial volume was around 549.2 mL.