Question

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?​.

Answer 1

54.03 moles of gas were left the next morning, assuming the temperature and volume of the tank stayed constant.

Explanation:

Status of the oxygen gas at night or initial conditions.

volume of the tank = 70 litre

temperature = 27 degree celsius or 300.15 K

pressure = ?

number of moles of oxygen = 119

R = 0.0821 L atm/mole K

applying gas law

PV = nRT

P = $\frac{0.0821 X 119.4 X 300.15}{70}$

P  = 42 atm

in the morning

volume  = 70 litres

temperature = 300.15 K

Pressure = 19 atm

n = ?

R =  0.0821 L atm/mole K

Applying  Ideal Gas law,

PV= nRT

putting the values in the formula:

n = $\frac{19 X 70}{0.0821 X 300.15}$

 n  = 54.03 moles will be left in the morning.