A man went from door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used ?

Question

A man went from door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used ?

Philoid · Accepted Answer

The solution used by the goldsmith was aqua-regia solution which contains concentrated nitric acid and concentrated hydrochloric acid in the ratio 1:3. When the gold bangles were dipped into this solution, considerable amount of gold was dissolved in it. Thus the weight of the bangle was reduced.