A balloon contains 30.0 L of helium gas at 103 kPa. What is the volume of the helium when the balloon rises to an altitude where the pressure is only 25.0 kPa? Assume that the temperature remains constant

To find the volume of the helium gas when the pressure changes, we can use Boyle's Law, which states that the pressure and volume of a gas are inversely proportional at constant temperature.

Boyle's Law equation is:
P₁V₁ = P₂V₂

Where:
P₁ = Initial pressure of the gas (103 kPa)
V₁ = Initial volume of the gas (30.0 L)
P₂ = Final pressure of the gas (25.0 kPa)
V₂ = Final volume of the gas (the value we want to find)

Using the equation, we can rearrange it to solve for V₂:
V₂ = (P₁V₁) / P₂

Now let's solve the equation using the given values:
V₂ = (103 kPa * 30.0 L) / 25.0 kPa

First, we need to convert kPa to L, as the units need to be consistent:
1 kPa = 1 L

V₂ = (103 L * 30.0 L) / 25.0 L
V₂ = 3090 L / 25.0
V₂ = 123.6 L

Therefore, the volume of the helium gas when the pressure is 25.0 kPa is approximately 123.6 L.