A 70-liter tank of oxygen gas at 27 degree Celcius and 42.0 atm springs a leak overnight. when the tank was found in the morning, the pressure in the tank had dropped to 19.0 atm. If the tank originally held 119.4 moles of oxygen gas, how many moles of gas were left the next morning, assuming the temperature and volume of the rank stayed constant?

54.0 mol

Explanation:

Given dа ta:

Initial pressure in tank = 42.0 atm

Initial moles in tank = 119.4 mol

Final pressure in tank = 19.0 atm

Final number of moles = ?

Solution:

According to ideal gas equation,

PV = nRT

P = n (RT/V)

pressure is directly proportional to the number of moles when R, T and v are kept constant.

P₁/n₁ = P₂/n₂

Now we will put the values.

42.0 atm / 119.4 mol = 19.0 atm / n₂

n₂ = 19.0 atm * 119.4 mol / 42.0 atm

n₂ = 2268.6 atm. mol / 42.0 atm

n₂ = 54.0 mol