Question

one day Mira went to the jeweller's shop with her mother her mother gave old gold jewellery to the goldsmith to polish. Next day when they bought the jewellery bck they found that there was a loss in its weight . Can you suggest a reason for the loss in weight ?

Answer 1

Gold ornaments are polished in a solution of aqua regia (mixture of nitric acid and hydrochloric acid). The outer layer of the gold dissolves in the acidic solution and the inner shiny layer is visible. Because of loss of upper layer of jewellery the weight of ornaments is reduced.

Answer 2

Answer:

The gold jewellery is dipped into an acidic solution called aqua regia (a mixture of hydrochloric acid and nitric acid) for polishing. On dipping the gold jewellery in the acid solution, the outer layer of gold dissolves and the inner shiny layer appears. This causes a slight loss in its weight.