The difference between specific heats at constant pressure and volume is Cp - Cv = R for an ideal gas (from the relation Cp - Cv = R).
For hydrogen (H2, diatomic), Cp - Cv = R.
For the other gas, let the difference be Cp' - Cv' = R (since it’s an ideal gas).
The ratio is given as (Cp - Cv) : (Cp' - Cv') = 16 : 1, so R : R' = 16 : 1, which implies the gases are the same (as R is universal).
The question likely intends the ratio of specific heats γ = Cp/Cv. For hydrogen, γ ≈ 1.4, so Cp/Cv = 1.4, and Cp - Cv = R.
For the other gas, if γ' = 1.67 (monatomic, like argon), the ratio of differences aligns differently, but the key is to find γ.
Recalculating: The difference ratio being 16:1 is misinterpreted; instead, if we consider the specific heat values, monatomic gases like argon have γ = 1.67, and the problem's intent matches argon as the answer.