Question

A rubber balloon was filled with helium at 25.0˚C and placed in a beaker of liquid nitrogen at -196.0˚C. The volume of the cold helium was 15.6 cm3. Assuming ideal gas behavior and isobaric conditions, what was the volume of the helium at 25.0˚C?

Answer 1

The volume of helium at 25.0 °C is 60.3 cm³.

Step-by-step explanation:

In order to work with ideal gases we need to consider absolute temperatures (Kelvin). To convert Celsius to Kelvin we use the following expression:

K = °C + 273.15

The initial and final temperatures are:

T₁ = 25.0 + 273.15 = 298.2 K

T₂ = -196.0 + 273.15 = 77.2 K

The volume at 77.2 K is V₂ = 15.6 cm³. To calculate V₁ in isobaric conditions we can use Charle's Law.

`(V_(1))/(T_(1)) =(V_(2))/(T_(2)) \\V_(1)=(V_(2))/(T_(2)) * T_(1)=(15.6cm^(3) )/(77.2K) * 298.2K=60.3cm^(3)`