Question

Molecule- Mass Conversions 1. How many molecules are there in 23.4 grams of magnesium?

Answer 1

Answer:

$5.78\times 10^{23}$ molecules

Explanation:

m = Mass of Magnesium = 23.4 g

M = Molar mass of Magnesium = 24.305 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

Number of moles is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{23.4}{24.305}\ \text{mol}$

Number of molecules is given by

$nN_A=\dfrac{23.4}{24.305}\times 6.022\times 10^{23}=5.78\times 10^{23}$

The sample has $5.78\times 10^{23}$ number of molecules.