Answer:
The answer to the question is
Chlorine Cl₂
Explanation:
Graham's Law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of the molar mass
0.238 =
Therefore M₁ = 4÷0.238² = 70.61
Hence the mass of the gas is 70.61, that is X₂ = 70.61 or the molar mass of the element X = 70.61÷2 = 35.308 ≅35.453 Hence the gas is chlorine Cl₂