Question

How many moles are contained with in 3.40*10^25 molecules SiO2

Answer 1

When we want to calculate the number of molecules, we need to take into consideration the relation between mole and number of molecules/atoms. One mole is, by definition, 6*10^23 entities, be they atoms or molecules.

In this case, 1 mole of SiO2 corresponds to 6*10^23 molecules of SiO2. By using this relationship, we can discover how many moles there are in 3.4*10^25 molecules. Let's set the following proportion:

`\begin{gathered} 1\text{ mole of SiO2 ------ 6}*10^(23)\text{ molecules} \\ x\text{ --------------- 3.4}*10^(25)\text{ molecules} \\ \\ x=(3.4*10^(25))/(6*10^(23))=(3.4)/(6)*10^(25-23)=0.56*10^2=56\text{ moles of SiO2} \end{gathered}`

So, 3.40*10^25 molecules of SiO2 correspond to 56 moles of SiO2.