This questions are about Moles.

Question

a. A mole represents how many particles? 

b. What is another name for this quantity?

c. I know the mass of a given substance. I need to convert that mass to moles. What is the conversion factor I need to do that?

Answer 1

A mole of anything is 6.022 x 10²³ items so a mole of hydrogen atoms is 6.022 x 10²³ atoms and a mole of carbon dioxide molecules is 6.022 x 10²³ molecules and a mole of kittens is 6.022 x 10²³ kittens (that's a lot of kittens!)

This quantity (6.022 x 10²³) is called Avogadro's number or the Avogadro constant.

If you know the mass of a substance (for instance "grams") and you want to know how many moles it is, you need to molar mass which is something you either calculate using the Periodic Table (items such as molecular compounds) or you just read it from the Periodic Table (for elements). The molar mass is usually the number of grams per mole.

Example: If you have 25 grams of Lithium, you look up on the Periodic Table that the molar mass of Lithium is 6.941 grams/mole then you divide 25 by 6.941 to get 3.6 moles. So 25 grams of Lithium is 3.6 moles. Then if you want to know how many atoms that is, you multiply 3.6 moles by 6.022 x 10²³ atoms/mole to get 2.2 x 10²⁴ atoms of Lithium

Answer 2

Hello Taylor,

a) 1 mole = 6.022*10^23 particles

(1 mole of anything is 6.022*10^23 of anything; for example, 1 mole of eggs is 6.022*10^23 eggs)

b) This number is also known as Avogadro's number

c) mass of a given substance * (moles of substance/molar mass of substance

I hope this helps!