At 25 degree celsius, which balloon has the greater volume, an oxygen balloon O2 at 1.2 atm with a mass of 16.0 g, or helium He balloon at 1.2 atm with a mass of 2.0 g?

Use PV = nRT, substitute the numbers, solve for volume, and compare the two.

To determine which balloon has the greater volume, we can use the ideal gas law, which states:

PV = nRT

Where:
P is the pressure in atm,
V is the volume in liters,
n is the number of moles of gas,
R is the ideal gas constant (0.0821 L·atm/(mol·K)),
T is the temperature in Kelvin.

First, let's convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15

Given:
Temperature (T) = 25°C = 25 + 273.15 = 298.15 K
Pressure (P) = 1.2 atm

Now, let's calculate the number of moles for each gas using the mass and molar mass:

For oxygen (O2):
Molar mass of O2 = 32.00 g/mol
Mass of O2 = 16.0 g

Number of moles of O2 = Mass of O2 / Molar mass of O2
= 16.0 g / 32.00 g/mol
= 0.5 mol

For helium (He):
Molar mass of He = 4.00 g/mol
Mass of He = 2.0 g

Number of moles of He = Mass of He / Molar mass of He
= 2.0 g / 4.00 g/mol
= 0.5 mol

Since both gases have the same number of moles (0.5 mol) and are at the same temperature (298.15 K) and pressure (1.2 atm), we can ignore these variables when comparing their volumes.

Therefore, we can conclude that both balloons have the same volume.