Notes of chemical reactions and aquations
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Answer:
The transformation of chemical substance into another chemical substance is known as Chemical Reaction. For example: Rusting of iron, the setting of milk into curd, digestion of food, respiration, etc.
In a chemical reaction, a new substance is formed which is completely different in properties from the original substance, so in a chemical reaction, a chemical change takes place.
Only a rearrangement of atoms takes place in a chemical reaction.
The substances which take part in a chemical reaction are called reactants.
The new substances produced as a result of a chemical reaction are called products.
Example: The burning of magnesium in the air to form magnesium oxide is an example of a chemical reaction.
2Mg(s) + O2(g) △→ 2MgO(s)
Before burning in air, the magnesium ribbon is cleaned by rubbing with sandpaper.
This is done to remove the protective layer of basic magnesium carbonate from the surface of the magnesium ribbon.
Reactant: Substances which take part in a chemical reaction are called reactants.
Example: Mg and O2.
Characteristics of Chemical Reactions :
(i) Evolution of gas: The chemical reaction between zinc and dilute sulphuric acid is characterised by the evolution of hydrogen gas.
Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) ↑
(ii) Change in Colour: The chemical reaction between citric acid and purple coloured potassium permanganate solution is characterised by a change in colour from purple to colourless.
The chemical reaction between sulphur dioxide gas and acidified potassium dichromate solution is characterized by a change in colour from orange to green.
(iii) Change in state of substance: The combustion reaction of candle wax is characterised by a change in state from solid to liquid and gas (because the wax is a solid, water formed by the combustion of wax is a liquid at room temperature whereas, carbon dioxide produced by the combustion of wax is a gas). There are some chemical reactions which can show more than one characteristics.
(iv) Change in temperature: The chemical reaction between quick lime water to form slaked lime is characterized by a change in temperature (which is a rise in temperature).
The chemical reaction between zinc granules and dilute sulphuric acid is also characterised by a change in temperature (which is a rise in temperature).
Chemical reaction -chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products
Aquation -Aquation is the chemical reaction involving "incorporation of one or more integral molecules of water" with or without displacement of other atoms or groups. The term is typically employed to refer to reactions of metal complexes where an anion is displaced by water.