derivation avogadro number
Answers
The number of molecules in one mole of any substance is constant. The Italian scientist Avogadro did fundamental work in this context. Therefore this number is called Avogadro’s number and is denoted by the symbol NA. Later scientists demonstrated experimentally that the value of Avogadro’s number is 6.022 x 1023. A mole of any substance stands for 6.022 x 1023 molecules. Just as a dozen has 12 items, a century has 100 or a gross has 144, a mole means 6.022 x 1023. For example, a mole of water, that is, 18g of water contains 6.022 x 1023 molecules of water.
How many molecules are there in 66 g of CO2?
Method : molecular mass of CO2 is 44.
Number of moles in the given CO2 (n) =mass of CO2 in grams/ molecular mass of CO2
= 66/44
. ं. n = 1.5 mol
. ं. 1 mol of CO2 contains 6.022 x 1023 molecules.
. ं. 1.5 mol CO2 contains 1.5 x 6.022x1023 molecules = 9.033 x 1023 molecules
