Question

I am holding a balloon containing 439 mL of gas over my fireplace. The temperature and pressure of the gas inside the balloon is 317.15 K and 0.959 atm, respectively. Suppose I don't want the pressure to change, but I want to the volume to go down to 0.378 L. What is the temperature that I need to reach when I cool down the balloon?

To what temperature (in Celsius) must the balloon be cooled to reduce its volume to 0.378 L if the pressure doesn't change (remained constant)?

Answer 1

-0.08 °C

Step-by-step explanation:

We can solve this problem by using Charles' law, which states that at constant pressure:

• V₁T₂ = V₂T₁

Where in this case:

• V₁ = 439 mL

• T₂ = ?

• V₂ = 0.378 L ⇒ 0.378 * 1000 = 378 mL

• T₁ = 317.15 K

We input the data:

• 439 mL * T₂ = 378 mL * 317.15 K

And solve for T₂:

• T₂ = 273.08 K

Finally we convert 273.08 K to Celsius:

• 273.08 K - 273.16 = -0.08 °C