question_answer 67)

  A silver ornament of mass 'm' gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.

Answer:

  Mass of silver (Ag) ornament = m g Mass of gold used for polishing Atomic mass of Ag = 108 u 1 mole of Ag = 108 g = 6.022 x 1023 atoms Thus,     108 g of Ag have atoms = 6.022 x 1023  mg of Ag will have atoms Similarly, atomic mass of gold (Au) = 197 u mole of Au = 197 g = 6.022 x1023 atoms Thus,     197 g of Au have atoms = 6.022 x 1023 0.01 m g of Au will have atoms Ratio of the number of atoms of gold and silver