Mol Stuff

Question 1

what is avogadros number

Answer 1

6.022 * 10^23 atoms

Question 2

Calculate the number of moles in 68 g of ammonia

Let 1 mol of ammonia be 17g

Answer 2

4 moles

Question 3

Calculate the number of molecules present in

0.5 moles of magnesium oxide

(MgO). [Atomic weights : Mg=24,O=16]

Answer 3

3.0115×1023
molecules

or just half a mol

Question 4

Calculate the number of moles of helium present in 52g of Helium.

1 mol of helium is 4 g

Answer 4

13 mols