Question

define Avogadro number write its value calculate mass of 0.2 mole of Oxygen give example of Democratic molecule

Answer 1

The Avogadro constant (symbols: L, NA) is the number of particles (usually atoms or molecules) in one mole of a given substance. Its value is equal to6.02214129(27)×1023 mol−1. ... Avogadro's number is a dimensionless quantity and has the numerical value of the Avogadro constant given in base units

Ans: Given number of moles = 0.2, molecular weight of Oxygen molecule (O₂) = 32

Number of moles = weight/ Molecular weight of Oxygen molecule

                     0.2  = weight/32

Weight =  0.2*32

            = 6.4 grams

Therefore mass of 0.2 moles of Oxygen molecule is equal to 6.4 grams.

Answer 2

Avogadro's number is the number of particle constituted in 1 mole of a substance and value of Avogadro's number equals to 6.022 ×10²³