Advertisements
Advertisements
Question
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
Advertisements
Solution
(i) Solid A is assumed to be MnO2 and solid B to be Aluminium (Al).
When the mixture of MnO2 and Al is heated, manganese (Mn) is produced in molten state and aluminium oxide (Al2O3) floats over it. Mn is produced in the molten state as a lot of heat energy is released in the process.
The chemical equation for the reaction can be written as:
3MnO2(s) + 4Al(s) `triangle/`> 3Mn(f) + 2Al2O3(s) + Heat
(ii) The types of reaction under which the above reaction is classified are—
-
Redox reaction
-
Displacement reaction
APPEARS IN
RELATED QUESTIONS
Two methods by which rusting of iron can be prevented are ______ and ______.
Write a chemical equation to show the process of corrosion of iron.
What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Compare roasting and calcination.
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
Write three methods of preventing rusting of iron.
The process of coating the surface of the metal with a thin layer of zinc is called ______
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
