A man went 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?

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Solution

He must have dipped the gold metal in the solution of aqua regia − a 3:1 mixture of conc. HCl and conc. HNO₃. Aqua regia is a fuming, highly corrosive liquid. It dissolves gold in it. After dipping the gold ornaments in aqua regia, the outer layer of gold gets dissolved and the inner shiny layer appears. That is why the weight of gold ornament reduced.

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Question 15
A man went 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?

Q. In a bangle shop, if the shopkeeper displays the bangles in the form of a square then he is left with 38 bangles with him. If he wanted to increase the size of square by one unit each side of the square he found that 25 bangles fall short of In completing the square. The actual number of bangles which he had with him in the shop was ________.

Q. A jeweler claims that he makes ornament of pure gold of relative density

19.3

. He sells a bangle weighing

25.25

gf to a person. The clever customer weighs the bangle when immersed in water and finds that it weighs

23.075

gf in water.With the help of suitable calculations find out whether the ornament is made of pure gold or not.
[HINT: calculate R.D. of material of bangle which comes out to be

11.6

Q. Identify the literary device used in the following passage:
Jesus said: A man was going down from Jerusalem to Jericho, when he was attacked by robbers. They stripped him of his clothes, beat him and went away, leaving him half dead. A priest happened to be going down the same road, and when he saw the man, he passed by on the other side. So too, a Levite, when he came to the place and saw him, passed by on the other side. But a Samaritan, as he traveled, came where the man was; and when he saw him, he took pity on him. He went to him and bandaged his wounds, pouring on oil and wine. Then he put the man on his own donkey, brought him to an inn and took care of him. The next day he took out two denariiand gave them to the innkeeper. Look after him, he said, and when I return, I will reimburse you for any extra expense you may have.

Q. A jeweller claims that he sells ornaments made of pure gold that has the relative density of 19.3. He sold a bangle weighing 25.25 gf to a person. The clever customer weighs that bangle when immersed in pure water and finds that it weighs 23.075 gf in water. Is the ornament made by pure gold?

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