Limitations of Dalton’s Law
This law is applicable only when the component gases in the mixture do not react with each other. For example, N2 and O2, CO and CO2, N2 and Cl2, CO and N2 etc. But this law is not applicable to gases which combine chemically. For example, H2 and Cl2, CO and Cl2, NH3, HBr and HCl, NO and O2 etc.
Another law, which is really equivalent to the law of partial pressures and related to the partial volumes of gases is known as Law of partial volumes given by Amagat. According to this law, “When two or more gases, which do not react chemically are kept in a closed vessel, the total volume exerted by the mixture is equal to the sum of the partial volumes of individual gases.”
Thus, Vtotal = V1+V2 +V3 +……..
Where V1+V2 +V3…… are partial volumes of gas number 1, 2, 3.....