The unit of length convenient on the atomic scale is known as an angstrom and is denoted by Å: 1 Å= 10-¹० m. The size of a hydrogen atom is about 0.5 Å. What is the total atomic volume in of a mole of hydrogen atoms ?
Given, the size of a hydrogen atom is about 0.5 A o . The volume of one hydrogen atom is, V= 4 3 ×π× r 3 = 4 3 ×π× ( 0.5 A o × 10 −10 m 1 A o ) 3 =5.236× 10 −31 m 3 One mole of hydrogen contains 6.023× 10 23 atoms. So, the total atomic volume of one mole of hydrogen atom is, V one mole =V×n =5.236× 10 −31 m 3 ×6.023× 10 23 =3.15× 10 −7 m 3 ≅3× 10 −7 m 3 Thus, the volume of one mole of hydrogen atom is ≅3× 10 −7 m 3 .
