Equimolar Ratio

When gases A, B, and C are mixed in an equimolar ratio, it means that the number of moles of each gas in the mixture is the same. To calculate the equivalent molecular mass (EMM) of the mixture, we need to consider the molecular masses of each gas and their respective mole fractions.

Step 1: Calculate the Mole Fraction
The mole fraction of a gas can be calculated by dividing the number of moles of that gas by the total number of moles in the mixture.

Mole fraction of gas A (Xa) = Moles of A / Total moles
Mole fraction of gas B (Xb) = Moles of B / Total moles
Mole fraction of gas C (Xc) = Moles of C / Total moles

Since the gases are mixed in an equimolar ratio, the number of moles of each gas is the same. Therefore, the mole fraction of each gas is 1/3.

Step 2: Calculate the Equivalent Molecular Mass
The EMM of the mixture can be calculated using the formula:

EMM = (Xa * Ma) + (Xb * Mb) + (Xc * Mc)

Where Ma, Mb, and Mc are the molecular masses of gases A, B, and C, respectively.

Example:
Let's consider an example where gases A, B, and C have molecular masses of 16 g/mol, 32 g/mol, and 28 g/mol, respectively.

Step 1: Calculate the Mole Fraction
Since the gases are mixed in an equimolar ratio, the mole fraction of each gas is 1/3.

Xa = Xb = Xc = 1/3

Step 2: Calculate the Equivalent Molecular Mass
EMM = (1/3 * 16) + (1/3 * 32) + (1/3 * 28)
= (16/3) + (32/3) + (28/3)
= (76/3)
= 25.33 g/mol

Therefore, when gases A, B, and C are mixed in an equimolar ratio, the EMM of the mixture is 25.33 g/mol.

By calculating the mole fraction and using the formula for EMM, we can find the EMM of a gas mixture when gases A, B, and C are mixed in an equimolar ratio.