Question

one day Rita went to a jeweler's shop with her mother . Her mother gave an old gold jewelery to the gold mith to polish . Next day when they brought the jewellery back, they found there a slight loss in it's weight . Can you suggest a reason for the loss in weight

Answer 1

The goldsmith must have dipped the jewelry in aqua regia and then polished it. This results in the decrease of weight of the jewelry as aqua regia can corrode almost anything.

Answer 2

The reason is that the jeweller has put the jewellery into aqua regia which is a mixture of nitric acid and hydrochloric acid in the ratio 1:3.
Aqua regia can dissolve gold and platinum metals into it . So when jeweller put the jewellery into aqua regia then it was dissolved into it