what is the number of moles ofo atom in 126 amu of HNO3 ?

Asked by Kaustubh Punit | 29th Jul, 2014, 09:53: AM

Expert Answer:

1 amu = 1.66 x 10-24 grams
126 amu = 126 x 1.66 x 10-24
              = 209.16 x 10-24 grams
1 mole HNO3 = 63.01 g
Hence 209.16 x 10-24 grams = 3.32 x 10-24 moles
 
1 mole = 6.023 x 1023 molecules
hence 3.32 x 10-24 moles = 19.99 x 1023  molecules
 
1 molecule of HNO3 contains 5 atoms.
Hence, 19.99 x 1023  molecules = 99.96 x 1023 atoms
 
Therefore, 126 amu of HNO3 contains 99.96 x 1023 atoms.

Answered by Prachi Sawant | 30th Jul, 2014, 02:19: PM