You have to put your attention to the unit of concentration. It is expressed in terms of molarity, which is represented in M. It is the number of moles solute per liter solution. So, you simply have to multiply the molarity with the volume in liters.
Volume = 275 mL * 1 L/1000 mL = 0.275 L
<em>Moles Ba(OH)₂ = (0.200 M)(0.275 L) = 0.055 mol</em>
Answer : The mole fraction and partial pressure of 
and 
gases are, 0.267, 0.179, 0.554 and 1.54, 1.03 and 3.20 atm respectively.
Explanation : Given,
Moles of 
= 1.79 mole
Moles of 
= 1.20 mole
Moles of = 3.71 mole
Now we have to calculate the mole fraction of and gases.
and,
and,
Thus, the mole fraction of and gases are, 0.267, 0.179 and 0.554 respectively.
Now we have to calculate the partial pressure of and gases.
According to the Raoult's law,
where,
= partial pressure of gas
= total pressure of gas = 5.78 atm
= mole fraction of gas
and,
and,
Thus, the partial pressure of and gases are, 1.54, 1.03 and 3.20 atm respectively.
MgF is an ionic compound because it's bond is between a metal and a non-metal
