Question

How many moles of nitrogen gas are there in 16.8 L of this gas at STP?

Answer 1

According to Avogadro's Law, same volume of any gas at standard temperature and pressure will occupy same volume. And one mole of any Ideal gas occupies 22.4 dm³ (1 dm³ = 1 L).

Data Given:

                  n = moles = ?
                  V = Volume = 16.8 L

Solution:
                As 22.4 L volume is occupied by one mole of gas then the 16.8 L of this gas will contain....

                           = ( 1 mole × 16.8 L) ÷ 22.4 L
                    
                           = 0.75 moles

Result:
           16.8 L of Nitrogen gas will contain 0.75 moles at standard temperature and pressure.