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प्रश्न
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?
उत्तर
The solution he used was Aqua regia, a Latin word meaning ‘Royal Water’. It is a mixture of concentrated Hydrochloric acid and concentrated nitric acid in a ratio of 3 : 1. It is capable of dissolving metals like Gold and Platinum. Since the outer layer of the gold bangles was dissolved in aqua regia, their weight was reduced drastically.
संबंधित प्रश्न
What chemical process is used for obtaining a metal from its oxide?
Why are the metals like Na, K, Ca and Mg never found in their free state in nature?
Name one metal which is extracted by reduction with carbon.
Name the gas evolved when cinnabar ore is roasted.
The metal which can be extracted simply by heating the cinnabar ore in air is:
(a) Zn
(b) Cu
(c) Al
(d) Hg
Zinc blende ore can be converted into zinc oxide by the process of:
(a) roasting
(b) hydrogenation
(c) chlorination
(d) calcination
A metal which exists as a liquid at room temperature is obtained by heating its sulphide ore in the presence of air.
(a) Name the metal and write its chemical symbol.
(b) Write the name and formula of the sulphide ore.
(c) Give the equations of chemical reactions involved in the production of metal from its sulphide ore.
(d) Name a common device in which this metal is used.
(e) Can this metal displace copper from copper sulphate solution? Why?
Give reasons, why aluminum is used in:
In aluminiothermy
Aluminum is used in thermite welding:
what is thermit?
Name the following:
Name two metals always find in combined state.
Define the term : Slag
Choose the correct answer from the options given below:
The metal is a liquid at room temperature.
Write the name.
The molecular formula of main ore of aluminium –
Write the name.
Metals which are amphoteric in nature.
Identify who I am!
Ore of Aluminum- ______
Explain the following reaction with the balanced equation.
Sodium aluminate reacts with water
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
- Given below are the steps for extraction of copper from its ore. Write the reaction involved.
- Roasting of copper (I) sulphide
- Reduction of copper (I) oxide with copper (I) sulphide.
- Electrolytic refining
- Draw a neat and well labelled diagram for electrolytic refining of copper
The given reaction shows one of the processes to extract the metals like Iron and Manganese.
\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]
Give the reason why the above reaction is known as a thermite reaction.
