Question

A cylinder with a movable piston records a volume of 12.6L when 3.0 mol of oxygen is added. The gas in the cylinder has a pressure of 5.83 atm. The cylinder develops a leak and the volume of gas is now recorded to be 12.1 L at the same pressure. How many moles of oxygen are lost?

Answer 1

Answer : The moles of oxygen gas lost are 2.88 mole

Explanation :

According to the Avogadro's Law, the volume is directly proportional to the number of moles of the gas at constant pressure and temperature.

$V\propto n$   (At constant temperature and pressure)

or,

$\frac{V_1}{V_2}=\frac{n_1}{n_2}$

where,

$V_1$ = initial volume of oxygen gas = 12.6 L

$V_2$ = final volume of oxygen gas = 12.1 L

$n_1$ = initial moles of oxygen gas = 3.0 mole

$n_2$ = final moles of oxygen gas = ?

Now put all the given values in the above formula, we get the final moles of oxygen gas.

$\frac{12.6L}{12.1L}=\frac{3.0mole}{n_2}$

$n_2=2.88mole$

Therefore, the moles of oxygen gas lost are 2.88 mole