What is the total number of molecules in 11.2 liters of N2 gas at STP?

The number of molecules is 3,01E23 of N2

Explanation:

We use the formula PV=nRT, and STP: 1 atm of pressure and 273 K of temperature.

PV=nRT  ---> n=PV/RT

n= 1 atm x 11,2 l /0,082 l atm/ Kmol x 273K

n= 0, 5 mol

We use the number of Avogadro:

1 mol6, 02E23 molecules

0,5 mol x= (0,5 mol x6, 02E23 molecules)/ 1 mol = 3,01E23

the answer is symmetrical : )