Question

Dalton’s law of partial pressure is applicable to which one of the following systems?
(A) $N{H_3}$+ $HCl$
(B) $NO$ + ${O_2}$
(C) ${H_2}$+ $C{l_2}$
(D) $CO$ + ${H_2}$

Answer 1

Hint: Dalton's law of partial pressure says that the total pressure of the mixture of gases is equal to the sum of the partial pressure of all the constituent gases. This law is not applicable to real gases that show a large deviation from pressure. Further, it is also not used for gases that may react with each other in the mixture forming product.

Complete step by step solution:
First, we will know what is dalton’s law of partial pressure,
Dalton's law of partial pressure states that the total pressure of the mixture of gases is equal to the sum of the partial pressure of all the constituent gases.
It can be mathematically written as -
${P_{Total}} = {p_1} + {p_2} + {p_3}...$
Where ${P_{Total}}$ is the partial pressure of all gases
And ${p_1}$ is the partial pressure of first gas
${p_2}$ is the partial pressure of second gas and so on.
Now, comes a term partial pressure.
The partial pressure can be defined as the pressure exerted by an individual gas in the mixture of all gases is called its partial pressure. This is the pressure that the gas would exert on the walls of the container if it was only present in the container.
Dalton’s law is used only when the component gases in the mixture do not react with each other. In case, the gases react with each other then the law is not applicable.
Now, let us see the options given to us.
The option (A) $N{H_3}$+ $HCl$. These gases react with each other. So, this law is not applied here.
In case of option (B) $NO$ + ${O_2}$. These gases can also react with each other. Again, the law is not applicable.
In option (C) ${H_2}$+ $C{l_2}$, the gases do react with each other giving two moles of HCl molecules. So, the law is not applicable.
In option (D) $CO$ + ${H_2}$, both the gases do not react with each other. So, the law will be applicable.

So, the option (D) is the correct answer.

Note: This law can also be expressed in terms of mole fraction. In terms of mole fraction. It states that partial pressure of a gas x is equal to the total pressure of all gases multiplied by the mole fraction of ‘x’ gas.
${p_x} = {x_1}{P_{Total}}$