Question

What is the no. Of ***** of O-atom in 126 amu of HNO3

Answer 1

Answer: We have

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 *****

1 mole = 6.023 x 1023 molecules

hence 3.32 x 10-24 ***** = 19.99 x 1023molecules

1 molecule of HNO3contains 5 atoms.

Hence, 19.99 x 1023molecules = 99.96 x 1023 atoms

Therefore, 126 amu of HNO3 contains 99.96 x 1023 atoms.