Acylinder 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 : 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.

  (At constant temperature and pressure)

or,

where,

= initial volume of oxygen gas = 12.6 L

= final volume of oxygen gas = 12.1 L

= initial moles of oxygen gas = 3.0 mole

= final moles of oxygen gas = ?

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

Therefore, the moles of oxygen gas lost are 2.88 mole

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)