Answer:
1.4 moles.
Explanation:
The following data were obtained from the question:
Initial mole (n1) = 1.8 moles
Initial pressure (P1) = 25.5 atm
Final pressure (P2) = 5.7 atm
Number of mole removed =?
Next, we shall obtain an expression relating pressure and number of mole together.
This is illustrated below:
From the ideal gas equation:
PV = nRT
Divide both side by V
P = nRT /V
Divide both side by n
P/n = RT/V
But volume (V) and temperature (T) are constant.
P/n = constant
P1/n1 = P2/n2
P1 is initial pressure.
P2 is final pressure.
n1 is the initial mole.
n2 is the final mole.
Next, we shall determine the final mole in tank as follow:
Initial mole (n1) = 1.8 moles
Initial pressure (P1) = 25.5 atm
Final pressure (P2) = 5.7 atm
Final mole (n2) =.?
P1/n1 = P2/n2
25.5/1.8 = 5.7/n2
Cross multiply
25.5 x n2 = 1.8 x 5.7
Divide both side by 25.5
n2 = (1.8 x 5.7) /25.5
n2 = 0.40 mole.
Therefore, the final mole in the tank is 0.40 mole.
Finally, we shall determine the number of mole that was removed as follow:
Initial mole (n1) = 1.8 moles
Final mole (n2) = 0.4 mole
Number of mole removed =?
The number of mole removed from the tank can be obtained by finding the difference between the initial mole and final mole as illustrated below:
Number of mole removed = initial mole – final mole
Number of mole removed = n1 – n2
Number of mole removed = 1.8 – 0.4
Number of mole removed = 1.4 moles
Therefore, 1.4 moles were removed from the tank.
