Q

# One day Reeta went to a jewellers shop with her mother. Her mother gave an old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back they found that there was a slight loss in its weight

Q11.  One day Reeta went to a jeweller’s shop with her mother. Her mother gave an old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?

Aqua regia (mixture of HCl and $\dpi{80} HNO_{3}$ in the ratio 3:1) is used to polish gold ornaments. When dipped in the liquid, the gold layer starts dissolving which causes a reduction in the weight. The outer unpolished layer dissolves and the layer becomes shiny.