Answer :
Final answer:
The identity of the gas is hydrogen.
Explanation:
To determine the identity of the gas, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin. Rearranging the equation, we get n = PV / RT. Plugging in the given values, we have n = (3.2 atm)(4.0 L) / (0.0821 L·atm/K·mol)(250 K) = 0.196. As the mass of the gas is 99.8 g, we can calculate the number of moles using the molar mass of the gas. Assuming the gas is ideal, we can convert grams to moles using the formula moles = mass / molar mass. The molar mass of hydrogen, helium, nitrogen, and oxygen are 2 g/mol, 4 g/mol, 28 g/mol, and 32 g/mol respectively. Calculating the moles for each gas, we find that the gas is hydrogen.