Question

One day Rita went to a jwellershop with mother. Her mother gave an old gold to Goldsmith to polish. Next day when they bought the jwellershop back, they found that there is a slight lose in its weight. Can you suggest a reason for the loss in wieght?

Answer 1

To polish the gold ornament the goldsmith use a liquid called aqua regia which is mixture of hydrochloric acid and nitric acids to clean jewellery. Usually gold doesn’t react with acids. But Aqua regia can dissolve gold. When gold is dipped in aqua regia the outer dull layer dissolves in aqua regia and the inner shiny layer appears. Due to this, some gold is lost during the polishing process. This causes the reduction in the weight.