Advertisements
Advertisements
प्रश्न
A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate.
In which test tube or test tubes will she observe colour change? On the basis of this experiment, state which one is the most reactive metal and why.
Advertisements
उत्तर
Test tube A : `Al + FeSO_4 -> Al_2(SO_4)_3 + Fe`
Iron sulphate is a green coloured solution. However, the resultant aluminium sulphate is colourless.
Test tube B : `Al + CuSO_4 -> Al_2 (SO_4)_3 + Cu`
Copper sulphate is a blue coloured solution. However, the resultant aluminium sulphate is colourless.
Test tube C: `Fe + Al_2(SO_4)_3 -> No reaction`
No reaction takes place here because aluminium is more reactive than iron.
Test Tube D : `Fe + CuSO_4 -> FeSO_4 + Cu`
Here, iron replaces copper and form ferrous sulphate which is a pale green coloured solution because iron is more reactive than copper.
Colour changes were observed in test tubes A, B and D.
Therefore, reactivity in decreasing order is: Al > Fe > Cu
Aluminium is the most reactive metal because it displaced both iron and copper from their compounds.
APPEARS IN
संबंधित प्रश्न
Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
| Metal | Iron (II) sulphate | Cooper (II) sulphate | Zinc sulphate | Silver nitrate |
| A | No reaction | Displacement | ||
| B | Displacement | No reaction | ||
| C | No reaction | No reaction | No reaction | Displacement |
| D | No reaction | No reaction | No reaction | No reaction |
Use the Table above to answer the following questions about metals A, B, C and D.
- Which is the most reactive metal?
- What would you observe if B is added to a solution of copper (II) sulphate?
- Arrange the metals A, B, C and D in the order of decreasing reactivity.
How would you show that silver is chemically less reactive than copper?
What happens when a rod of zinc metal is dipped into a solution of copper sulphate? Give chemical equation of the reaction involved.
Metal A burns in air, on heating, to form an oxide A2O3 whereas another metal B burns in air only on strong heating to form an oxide BO. The two oxides A2O3 and BO can react with hydrochloric acid as well as sodium hydroxide solution to form the corresponding salts and water.
(a) What is the nature of oxide A2O3?
(b) What is the nature of oxide BO?
(c) Name one metal like A.
(b) Name one metal like B.
Write the name and formula of a molecule made up of three atoms of oxygen.
Write a chemical equation to illustrate the use of aluminium for joining cracked railway lines.
Write the chemical equation of the above process.
Answer the following question:
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is metal or a non - metal. Explain with a proper example.
Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?
Find the odd one out:
