Padhle 10th - Chemical Reactions & Equations + Integrated PYQs

Chemical Reaction

A process in which bonds are broken within reactant molecules, and new bonds are formed to create a new substance.

Observations of Chemical Reactions

Indicators that a chemical reaction has taken place include: change in state, change in color, change in temperature, evolution of gas, formation of precipitate.

Chemical Equation

A symbolic representation of a chemical reaction showing the reactants and products.

Balancing a Chemical Equation

The process of ensuring that the number of each type of atom is the same on both sides of a chemical equation.

Physical States Notations

The physical states of reactants and products are indicated in equations as: (g) for gas, (l) for liquid, (s) for solid, and (aq) for aqueous.

Combination Reaction Definition

A reaction in which two or more substances combine to form a single product.

Decomposition Reaction Definition

A reaction in which a compound breaks down into two or more simpler substances.

Exothermic Reaction

A chemical reaction that releases heat.

Endothermic Reaction

A chemical reaction that absorbs heat.

Displacement Reaction

A reaction in which a more reactive element displaces a less reactive element from its compound.

Double Displacement Reaction

A reaction in which two compounds react and exchange ions to form two new compounds.

Oxidation

The process where a substance gains oxygen or loses electrons.

Reduction

The process where a substance loses oxygen or gains electrons.

Corrosion

The deterioration of a metal due to chemical reactions in the environment.

Rancidity

The process of oxidation of fats and oils leading to unpleasant smells and tastes.

Chemical Formula

A representation of a chemical substance using symbols for its constituent elements.

Word Equation

A method of expressing a chemical reaction using the names of the reactants and products.

Balanced Chemical Equation Example

An example of a balanced equation for the reaction of sodium and water is: 2Na + 2H2O → 2NaOH + H2.

Electrolysis of Water

The process of using electricity to decompose water into oxygen and hydrogen gas.