Which one of the following will have the largest number of atoms? [Au=197,Na=23,Li=7,Cl=35.5 in amu]
(1) 1g Au(s) (2) 1g Na(s)
(3) 1g Li(s) (4) 1g Cl2(g)
Which one of the following will have the largest number of atoms? [Au=197,Na=23,Li=7,Cl=35.5 in amu]
(1) 1g Au(s) (2) 1g Na(s)
(3) 1g Li(s) (4) 1g Cl2(g)
(1) 1 g of Au (s) 
mol of Au (s)
atoms of Au (s)
= 3.06 × 1021atoms of Au (s)
(2) 1 g of Na (s) = 
mol of Na (s)
atoms of Na (s)
= 0.262 × 1023 atoms of Na (s)
= 26.2 × 1021 atoms of Na (s)
(3) 1 g of Li (s) 
mol of Li (s)
atoms of Li (s)
= 0.86 × 1023 atoms of Li (s)
= 86.0 × 1021 atoms of Li (s)
(4) 1 g of Cl2 (g) 
mol of Cl2 (g)
(Molar mass of Cl2 molecule = 35.5 × 2 = 71 g mol–1)
molecules of Cl2 (g)
= 0.0848 × 1023 molecules of Cl2 (g)
= 8.48 × 1021 molecules of Cl2 (g)
As one molecule of Cl2 contains two atoms of Cl.
Number of atoms of Cl = 2× 8.48 × 1021 =16.96 × 1021 atoms of Cl
Hence, 1 g of Li (s) will have the largest number of atoms.
(1) 1 g of Au (s) mol of Au (s)
atoms of Au (s)
= 3.06 × 1021atoms of Au (s)
(2) 1 g of Na (s) = mol of Na (s)
atoms of Na (s)
= 0.262 × 1023 atoms of Na (s)
= 26.2 × 1021 atoms of Na (s)
(3) 1 g of Li (s) mol of Li (s)
atoms of Li (s)
= 0.86 × 1023 atoms of Li (s)
= 86.0 × 1021 atoms of Li (s)
(4) 1 g of Cl2 (g) mol of Cl2 (g)
(Molar mass of Cl2 molecule = 35.5 × 2 = 71 g mol–1)
molecules of Cl2 (g)
= 0.0848 × 1023 molecules of Cl2 (g)
= 8.48 × 1021 molecules of Cl2 (g)
As one molecule of Cl2 contains two atoms of Cl.
Number of atoms of Cl = 2× 8.48 × 1021 =16.96 × 1021 atoms of Cl
Hence, 1 g of Li (s) will have the largest number of atoms.
