Question

Calulate the number of atoms in each of the following (i) 52 moles of Ar (ii) 52u of He​

Answer 1

Answer:

(i) 1 mole of Ar =6.022×1023 atoms of Ar

52 mol of Ar=52×6.022×1023 atoms of Ar

          =3.131×1025 atoms of Ar

(ii) Atomic mass of He = 4amu

Or

4amu is the mass of He atoms = 1

Therefore 52 amu is the mass of He atoms=0.25×52=13 atoms of He

(iii) Gram atomic mass of He = 4g

Or

4g of He contains =6.022×1023 atoms

Therefore 52 g of He contains=4×526.022×1023=7.83×1024atoms