Chemical Reactions and Equations
Chemical Reactions
A chemical reaction occurs when one or more reactants are changed into one or
more products. The constituent atoms of the reactants are rearranged in a chemical
reaction, resulting in the formation of various substances as products.
Physical and Chemical Changes
Chemical change – one or more new substances with new physical and chemical
properties are formed.
Here, when copper sulphate reacts with iron, two new substances, i.e., ferrous
sulphate and copper, are formed.
Physical change – change in colour or state occurs, but no new substance is formed.
Example: Water changes to steam on boiling, but no new substance is formed (Even
though steam and water look different when they are made to react with a piece of
Na, they react the same way and give the exact same products). This involves only a
change in state (liquid to vapour).
, Observations that Help Determine a Chemical Reaction
A chemical reaction can be determined with the help of any of the following
observations.
a) Evolution of a gas
b) Change in temperature
c) Formation of a precipitate
d) Change in colour
e) Change of state
Chemical Reaction
Chemical reactions are chemical changes in which reactants transform into products
by making or breaking bonds (or both) between different atoms.
A chemical reaction is a process that causes one set of chemical components to
change into another. Chemical reactions are defined as changes in the locations of
electrons in the formation and breaking of chemical bonds between atoms, with no
change in the nuclei, and are described using a chemical equation. At a given
temperature and chemical concentration, chemical reactions occur at a predictable
rate. Reaction speeds often increase as the temperature rises because more thermal
energy is available to attain the activation energy required to break bonds between
atoms.
Types of Chemical Reactions
Taking into consideration different factors, chemical reactions are grouped into
multiple categories.
A few examples are:
● Combination
● Decomposition
● Single Displacement
● Double displacement
● Redox
● Endothermic
● Exothermic
● Precipitation
● Neutralisation
Chemical Reactions
A chemical reaction occurs when one or more reactants are changed into one or
more products. The constituent atoms of the reactants are rearranged in a chemical
reaction, resulting in the formation of various substances as products.
Physical and Chemical Changes
Chemical change – one or more new substances with new physical and chemical
properties are formed.
Here, when copper sulphate reacts with iron, two new substances, i.e., ferrous
sulphate and copper, are formed.
Physical change – change in colour or state occurs, but no new substance is formed.
Example: Water changes to steam on boiling, but no new substance is formed (Even
though steam and water look different when they are made to react with a piece of
Na, they react the same way and give the exact same products). This involves only a
change in state (liquid to vapour).
, Observations that Help Determine a Chemical Reaction
A chemical reaction can be determined with the help of any of the following
observations.
a) Evolution of a gas
b) Change in temperature
c) Formation of a precipitate
d) Change in colour
e) Change of state
Chemical Reaction
Chemical reactions are chemical changes in which reactants transform into products
by making or breaking bonds (or both) between different atoms.
A chemical reaction is a process that causes one set of chemical components to
change into another. Chemical reactions are defined as changes in the locations of
electrons in the formation and breaking of chemical bonds between atoms, with no
change in the nuclei, and are described using a chemical equation. At a given
temperature and chemical concentration, chemical reactions occur at a predictable
rate. Reaction speeds often increase as the temperature rises because more thermal
energy is available to attain the activation energy required to break bonds between
atoms.
Types of Chemical Reactions
Taking into consideration different factors, chemical reactions are grouped into
multiple categories.
A few examples are:
● Combination
● Decomposition
● Single Displacement
● Double displacement
● Redox
● Endothermic
● Exothermic
● Precipitation
● Neutralisation
