Question

The molality of pure gas A is 25/1.1 and pure gas B is 100/6.4. now a gaseous solution was prepared by mixing pure gas A and B. the molarity of gas A in gaseous solution at 10 atm and 200/0.821 K temperature is 0.1 M. find molality of gas a in the solution

Answer 1

in the question since it is not mentioned about the quantity of each gas taken in the mixture i assume that equal masses of each gas is mixed, therefore molality of each gas should decrease by half of original molality.  But in this question since the molarity is 0.1 hence  total volume of the mixture is calculated as follows
 0.1 = 10 x V / 0.0821 x 200 / 0.821 
 hence volume of gaseous solution = 200ml
if mass of solution = volume of solution than molality = 0.1 x 1000/ 200=0.5