How many atoms are there in 0.5g of water?
Answers
Answer:
First thing to do is to find no. of moles in 0.05g of HOH
molecular weight of HOH =18 g mol^-1
n = weight of HOH/ molecular weight=0.05/18=2.78*10^-3 mol
Then no. of molecules of HOH in 2.78*10^-3 mol is
No. of molecule= n* Avogadro no.= 2.78*(10^-3) * 6.022*(10^23)=16.74*10^20 molecules of HOH
Now move towards question, its given no. of atom and not no. of molecules. Hence for every molecule of HOH there are three atoms, two of H and one of O.
Hence final answer is 3(16.74)*10^20= 50*10^20=5*10^21
Explanation:
Answer:
4.8762×10²² atoms
Explanation:
No. of moles= Mass/ Mr
Mr of H²0 =(1×2)+(16×1)
= 18
No. of moles= 0.5÷18
=0.027 mol
•1 mole of H²O contains 3 mol of atoms
•0.027 mol of H²0 contains 3×0.027 mol of atoms
= 0.081 mol of atoms
No. of atoms= No. of moles× NA
0.081×6.02×10²³
= 4.8762×10²² atoms