Question

15. If a piston chamber at constant pressure initially contains 1215 mL of a gas, what was

the initial temperature if after heating to 111°C the new volume is 1.39 L?

Answer 1

To find the initial temperature of the gas, Charles's Law is applied. After converting the volumes into liters and the final temperature into Kelvin, the formula (V1/T1 = V2/T2) is used to calculate the initial temperature, which is approximately 62.22°C.

Step-by-step explanation:

The student's question involves applying Charles's Law, which describes how gases tend to expand when heated. The law states that for a given mass of gas at constant pressure, the volume is directly proportional to the temperature (in Kelvin). The initial volume is 1215 mL which we convert to liters as 1.215 L. The final volume is given as 1.39 L, and the final temperature is 111°C, which converts to 384.15 K (111 + 273.15).

To find the initial temperature (T1), we can use the formula derived from Charles's Law:

V1/T1 = V2/T2

Substituting the given values, we get:

1.215 L / T1 = 1.39 L / 384.15 K

We solve for T1 to find the initial temperature:

T1 = (1.215 L × 384.15 K) / 1.39 L

T1 = approximately 335.37 K

Then we convert 335.37 K back to Celsius by subtracting 273.15:

T1 ≈ 62.22°C

The initial temperature of the gas was approximately 62.22°C.