How many moles does 8.19 L of gas at STP represent?

Explanation:

           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.

answer: i would say b.

explanation:

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.