Hi Muhammad,

The nature of the flow will be a function of the ratio of initial pressure of the tank to the outlet pressure. You may observe choking until the inside pressure goes below a specific value. I suggest you read the following guides:

1. https://www.lmnoeng.com/Gas/choke.php

2. Dutton, J. C., & Coverdill, R. E. (1997). Experiments to study the gaseous discharge and filling of vessels. International Journal of Engineering Education, 13(2), 123-134.

Good luck

According to the gas state equation pV=nRT, it is not enough to know the initial pressure p1 and the final pressure p2. At least two state temperature or container volume parameters are required. I think your problem and known conditions are not clear enough.

Typically, you assume the process to be adiabatic and use the ideal gas law. Using these two assumptions with the conservation of mass, you can determine the flow rate.