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प्रश्न
Explain the following type of chemical reaction, giving two examples for it:
Displacement reaction
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उत्तर
A displacement reaction occurs when a more active element displaces a less active element from a compound.
Examples:
- Zinc displaces copper from copper sulphate solution.
\[\ce{Zn + CuSO4_{(aq)} -> ZnSO4_{(aq)} + Cu}\] - Iron pieces when added to copper sulphate solution, copper is displaced.
\[\ce{Fe + CuSO4 → FeSO4 + Cu}\]
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संबंधित प्रश्न
CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s) is an example of a decomposition reaction.
State two characteristics of the chemical reaction which takes place when dilute sulphuric acid is poured over zinc granules.
Why does the colour of copper sulphate solution change when an iron nail is kept immersed in it?
A strip of metal X is dipped in a blue coloured salt solution YSO4. After some time, a layer of metal Y from the salt solution is formed on the surface of metal strip X. Metal X is used in galvanisation whereas metal Y is used in making electric wires. Metal X and metal Y together form an alloy Z.
(a) What could metal X be?
(b) What could metal Y be?
(c) Name the metal salt YSO4.
(d) What type of chemical reaction takes place when metal X reacts with salt solution YSO4? Write the equation of the chemical reaction involved.
(e) Name the alloy Z.
When a black metal compound XO is heated with a colourless gas Y2, then metal X and another compound Y2O are formed. Metal X is red-brown in colour which does not react with dilute acids at all. Gas Y2 can be prepared by the action of a dilute acid on any active metal. The compound Y2O is a liquid at room temperature which can turn anhydrous copper sulphate blue.
(a) What do you think is metal X?
(b) What could be gas Y2?
(c) What is compound XO?
(d) What is compound Y2O?
(e) Write the chemical equation of the reaction which takes place on heating XO with Y2.
(f) What type of chemical reaction is illustrated in the above equation?
When a strip of red-brown metal X is placed in a colourless salt solution YNO3 then metal Y is set free and a blue coloured salt solution X(NO3)2 is formed. The liberated metal Y forms a shining white deposit on the strip of metal X.
(a) What do you think metal X is?
(b) Name the salt YNO3.
(c) What could be metal Y?
(d) Name the salt X(NO3)2.
(e) What type of reaction takes place between metal X and salt solution YNO3?
To show that zinc is a more active metal than copper, the correct procedure is to:
(1) add dilute nitric acid on strips of both the metals.
(2) observe transmission of heat through strips of zinc and copper.
(3) prepare solution of zinc sulphate and hang strip of copper into it.
(4) prepare solution of copper sulphate and hang strip of zinc into it.
Classify the following reaction into different type:
AgNO3(aq) + NaCl(aq) →AgCl(s) + NaNO3(aq)
Classify the following reaction into different type:
Zn + CuSO4 → ZnSO4 + Cu
\[\ce{Pb + CuCl2 -> PbCl2 + Cu}\]
The above reaction is an example of:
