# Chemistry help please ?

Thank you so much !!!

### 1 Answer

- hcbiochemLv 71 month agoFavourite answer
What your answers are will depend on what you have been taught is the molar volume of a gas at STP (which depends on what you were taught are the standard conditions of temperature and pressure). The "old" standard temperature and pressure were defined as 1 atm pressure and 273.15 K. Under these conditions, one mole of an ideal gas has a volume of 22.414 L/mol.

More recently, the standard conditions have been defined as 100 kPa and 273.15 K. By this definition, 1 mole of an ideal gas has a volume of 22.711 L/mol.

Unfortunately, the older value is what is still commonly taught, at least in the US. So, I'll use that old value:

a. 2.50 L X (1 mol / 22.414 L) = 0.112 mol NH3

b. 0.112 mol NH3 X 17.02 g/mol = 1.90 g NH3

c. 0.112 mol X 6.022X10^23 molecules/mole = 6.72X10^22 molecules NH3

d. 6.72X10^23 molecules X (3 H atoms/1 molecule) = 2.02X10^23 H atoms