Puspak Sah

# Limestone doesn't exist out in the world as pure calcium carbonate for the most part, and making it into a pure substance usually requires some kind of processing. Mostly, this is us making a distinction between calcium carbonate (the compound) and limestone (the material out in the world).

# The atomic masses of most elements are fractional because they exist as a mixture of isotopes of different masses.Most elements occur as a mixture of isotopes of different masses. The fractional atomic...

Method 1 :

Hit and Trial Method:

The simplest method to balance a chemical equation is by the hit and trial method. This method is also called trial and error method, or inspection method. In this method, coefficient before the formulae or symbols of the reactants and products are adjusted in such a way that the total number of atoms of each element only both the sides become equal. This is called material balance, or mass balance. In this method first of all, atoms of the element which appears...

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants.

Examples :

i. Combustion

ii. Oxidation (rusting

iii. Decomposition or fermentation

iv. Photosynthesis

v. Reacting acids and bases together.

The different types of chemical reaction are

1.Combination reaction:

In...

All that is implied by the chemical equation 2H₂ + O₂ 2H₂O are

It explains that on hydrolysis of water we get hydrogenation and oxygen as a product.

# Molecular mass ofH₂=2 g/mol

# Molecular mass ofO₂=32 g/mol

From the balanced chemical equation,

2 2=4 g of hydrogen requires 32 g of Oxygen to react completely.

# Limitations of this equation are

1. It doesn't give the conditions required to carry out chemical equation.

2. It doesn't tell whether heat is absorbed or evolved in the reaction unless the...

Chemical equations are symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.

The burning of wood leads to the formation of new substances like ash (carbon), carbon dioxide gas, water vapour, heat and light. This change is irreversible and hence, considered as chemical change.

Some significance of chemical equation are :

1. It explains the specific conditions of temperature,...

The changes in which new substance with new chemical properties are formed are called chemical change.

Example: Reaction between washing soda and lemon juice in which CO and other substances are formed.

Original substances participating in a chemical reaction are known as the reactants.

The new substance formed after chemical reaction are known as the products.

The general characteristics of a chemical reaction are :

i). Evolution of gas

ii). Formation of a precipitate

iii). Change in...