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प्रश्न
What is meant by chemical reaction? Explain with the help of an example.
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उत्तर
Chemical reaction is the process in which atoms of some elements rearrange—that is, undergo a chemical change—to form a new product with different properties. This involves breaking of old bonds between the reacting atoms and making of new chemical bonds between the rearranged atoms.
For example, the burning of magnesium ribbon in air. In this reaction, magnesium ribbon, on heating, combines with oxygen to form a white powder of magnesium oxide, which is totally different in its properties from magnesium and oxygen.
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संबंधित प्रश्न
What is wrong with the following chemical equation?
Mg + O → MgO
Correct and balance it.
Complete and balance the following equation:
NaOH + ............ 
Na2 SO4 + H2O
Balance the following equation:
Na + O2 
Na2O
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(a) What is metal M?
(b) What is solution S? Is it acidic or alkaline?
(c) What is gas G?
(d) Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
(e) Is this reaction exothermic or endothermic?
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potassium dichromate + hydrochloric acid → Potassium chloride + chromium chloride + water + chlorine
Write the balanced chemical equation of the following reaction.
sodium chloride + manganese dioxide + sulphuric acid → sodium hydrogen sulphate + manganese sulphate + water + chlorine.
Name the following:
The gas evolved when a dilute acid is added to chalk [limestone].
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
Give a reason why the above equation is balanced.
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ZnS + O2 → ZnO + SO2
Balance the following simple equation:
KHCO3 → K2CO3 + H2O + CO2
Write a balanced equation for the following word equation:
Iron + Hydrochloric acid → Iron [II] chloride + Hydrogen
