This problem is providing the volume, temperature and pressure of a gas and asks for the number of moles at such conditions, which turns out to be 0.0160 mol.
In chemistry, we study ideal gases, which are assumed to be perfectly spherical and with no relevant neither attractions nor repulsions among molecules, with the widely-known ideal gas equation relating volume, temperature, pressure and moles as follows:
[tex]PV=nRT[/tex]
Thus, knowing it is in a 0.300-L vessel at 15.0 °C and 157.6 kPa, one can solve for n in the previous equation to get:
[tex]n=\frac{PV}{RT}[/tex]
And plug in by making sure the pressure is in atmospheres and the temperature in kelvins:
[tex]n=\frac{157.6kPa*\frac{1atm}{101.325kPa}*0.300L}{(0.08206\frac{atm*L}{mol*K})*(15.0+273.15)K}\\\\n=0.0160mol[/tex]
Learn more about ideal gases: brainly.com/question/8711877
