Answer:
answer: 6.875 moles
Explanation:
nCH4 = nCO2 = 110/(12 + 4) = 6.875
Answer : The partial pressure of X and Y gases are, 0.525 and 1.575 atm respectively.
Explanation : Given,
Moles of X = 2.0 mole
Moles of Y = 6.0 mole
Total pressure = 2.1 atm
Now we have to calculate the mole fraction of X and Y.


and,


Now we have to calculate the partial pressure of X and Y.
According to the Raoult's law,

where,
= partial pressure of gas
= total pressure of gas = 2.1 atm
= mole fraction of gas


and,


Thus, the partial pressure of X and Y gases are, 0.525 and 1.575 atm respectively.
The best way to express the concentration of a solution depends on the use of the information.
Some ways to express the concentration are: percent mass/mass, percen mass/volumen, percent volume/volume, ppm, molaritiy, molality, normality, mole fraction, among others.
If I am not going to perform a special chemical calculation (like pH or acid/base neutralization, or a colligative property) I'd probably rather to use percent mass/mass.
Percent mass/mass is an easy and intuitive way to understand how concentrated a solution is.
For example, it is easy for you to grasp that a 10% solution of NaCl has the double amount of salt than a 20% solution of NaCl.
But if you want to calculate a colligatiive property like the boiling point increase or freezing point depression of a solvent you need the molality of the solution.
And if you want to calculate the pH of a solution, you will need to know the molarity.
If you are working with very low concentrations, for example the amount of lead in a sample of a food ingredient, you'd rather work with ppm.
Each concentration measure has its own use.