Answer:
The mass of N2 is 25 grams.
Explanation:
We use the formula PV=nRT and STP:1 atm of pressure and 273 K of temperature. The weight of 1 mol of N2 is: 14g/mol x2= 28g/mol.
PV=nRT
n=PV/RT= 1atm x20l /0,082 l atm/K mol x 273K
n= 0,89 mol
1 mol N2-----28 grams
0,89 mol N2---X=(0,89 mol N2x 28 grams)/1 mol N2=25 grams N2