Understand About the Chemical Reaction & Problems

A chemical reaction is a process in which reactants react chemically and then undergo chemical transformation to become products. For instance, when humans breathe in oxygen, it combines with glucose to make carbon dioxide, water, and energy.

Chemical Reaction Characteristics

Chemical reactions exhibit one or more of the properties listed below.

• Evolution of gas 

• Change in colour

• Change in temperature 

• Change in energy

• Formation of precipitate 

• Change in state

Now you know everything there is to know about these features.

Gas Evolution – As gas evolves, it undergoes some chemical processes. When zinc combines with hydrochloric acid, for example, hydrogen gas is produced, and zinc chloride is formed. 

Reaction – Zn + 2HCl → ZnCl2 + H2

Change in Colour – Some chemical reactions are followed by a colour change. When colourless lead nitrate interacts with potassium iodide, for example, a yellow precipitate of lead iodide and colourless potassium nitrate is formed.

Reaction – Pb(NO3)2     +   2KI          →               PbI2           +      2KNO3

                        Colourless            Colourless                     Yellow ppt colourless

Change in Temperature – Some chemical reactions are followed by a temperature change. Some reactions, for example, are exothermic, while others are endothermic. 

Change in Energy – Chemical processes frequently include energy changes. Energy can be released or absorbed during a chemical process. Energy is released in combustion reactions, such as the burning of a fuel, for example.

Formation of Precipitate – Precipitate formation is a side effect of some chemical processes. Barium chloride, for example, interacts with sodium sulphate to generate sodium chloride and barium sulphate precipitate.

Reaction – BaCl2 + Na2SO4   —>     BaSO4           +        NaCl

                                                            Precipitate 

Change in State – A change in state is followed by some chemical processes. Ammonia gas, for example, combines with hydrogen chloride gas to generate solid ammonium chloride crystals.

Reaction – NH3(g) + HCl(g) —->  NH4Cl(s)

Types of Chemical Reactions 

There are many different types of chemical reactions. We’ll go over the eight most prevalent types of chemical reactions, which are also covered in the chemistry curriculum for class X.

• Decomposition reaction 

• Combination reaction 

• Combustion reaction 

• Neutralization reaction 

• Single displacement reaction 

• Double displacement reaction 

• Precipitation reaction 

• Redox reaction

Decomposition Reaction –

Molecules or compounds decompose into two or more simpler chemically novel entities in a decomposition reaction. Take, for example, water electrolysis. Water breaks down into hydrogen and oxygen during electrolysis, which have fundamentally different properties than water.

Reaction – 2H2O electricity → 2H2 + O2

Combination Reaction –

Two or more molecules are chemically mixed to generate a new substance in a combination reaction (compound). The reactions of combination and breakdown are diametrically opposed. When we burn magnesium ribbon (or magnesium), for example, we get a grey-black ash of magnesium oxide. 

Reaction – Mg + O2 → MgO

Combustion Reaction –

It’s an exothermic reaction in which energy is released, usually in the form of heat. It’s a reaction that produces smoke, water, and heat when fuel and an oxidant (usually air oxygen) come together. When we burn methane, for example, we get carbon dioxide and water.

Reaction – CH4 + 2O2 → CO2 + 2H2O

Neutralization Reaction –

Acid and base react with each other to generate salt and water in these reactions. Hydrochloric acid, for example, interacts with sodium hydroxide (base) to produce sodium chloride (salt) and water. 

Single Displacement Reaction –

More reactive metal displaces less reactive metal from its salt in a single displacement reaction. Reactivity series can be used to determine the products in these reactions. The reactivity series is a set of items grouped in decreasing order of reactivity. It indicates that the elements at the top of the reactivity scale are more reactive than those at the bottom.

A single displacement reaction is the reaction of potassium with magnesium chloride. Because potassium is more reactive than magnesium, it displaces magnesium from its salt in this reaction. Potassium is the most reactive element and is found at the top of the reactivity scale.

Reaction –   2K + MgCl2 → 2KCl + Mg

Double displacement reaction –

Two aqueous ionic compounds exchange their ions (mainly cations) and form two new compounds in a double displacement process. Potassium nitrate, for example, interacts with aluminium chloride to produce aluminium nitrate and potassium chloride.

Reaction – KNO3 + AlCl3 ↔️    Al(NO3)3 + KCl

Precipitation Reaction –

These reactions result in the formation of an insoluble precipitate. Two soluble salts in aqueous solutions are joined in precipitation processes to generate an insoluble precipitate.

Reaction – AgNO3(aq) + KCl(aq) ↔️    AgCl + KNO3(aq)

Redox Reaction –

Redox reactions are chemical reactions that involve both oxidation and reduction at the same time. The addition of oxygen is oxidation, while the addition of hydrogen is reduction (or removal of oxygen). Oxidation and reduction have already been explored in a separate article titled ‘Oxidation and Reduction.’

Conclusion

Chemical reactions occur frequently in our daily lives, and we are aware of many of them. On the surface of various iron goods, such as the bodies of automobiles, gates, and so on, we frequently find a flaky brown coloured layer. During Diwali’s festivities and celebrations, we ignite crackers, which produce a dazzling light and sound when lit. The dazzling light is caused by the combustion of components such as magnesium, which is one of the chemicals in the crackers and sparklers we utilise. In this post, we’ll look at some of the chemical processes that we witness in everyday life.