What are acids and bases? - Acids, Bases and Salts - CBSE Class 7 Science Video Lecture

good morning children today we shall
learn about acid and pace we already
know about the acid rains the harmful
air pollutants like the carbon dioxide
and the other oxides etc get mixed with
rain drops and form harmful substances
called acid this acid rain reduces the
fertility of soil and also damages trees
and the monuments you know this acid
rain is also damaging the stones of Taj
Mahal the pride of India the same
substance acid is produced by the jumps
by rotting the food in the teeth and
then this acid decays the teeth causing
cavity and thus we have tooth cavity but
when we are thinking of acid as bad we
must also know our muscles are made of
proteins which is made of an acid amino
acid even many nutrients which are
necessary for a growth and nutrition
like the vitamins fat etc are made of
acid so as it helps us in our growth and
nutrition so acids are very important
and certain acids are very harmful but
what is an acid many kids like sour
fruits like lemons tam red unripe
mangoes etc isn't it if we like sir that
means you like acidic nature of roots
how this our taste is the property of
assets the chemical nature of acid is
called the acidic nature
it means sour fruits have acid and those
fruits ours are due to the acidic nature
the acid word comes from Latin word as
he does which means are but you know the
powerful as
it's can also be corrosive that is it
can harm our skin and even burn our skin
when it comes in contact with us so all
the assets cannot be tasted acids which
are found naturally in the plants
animals and other living things are
referred to as organic acid for example
the citric acid in lemon malic acid in
Apple's vitamin C is actually ascorbic
acid lactic acid is in the milk the
common vinegar which we all use in food
is called the acetic acid
you know formic acid is found in the bee
and the ant sting when an ant stings it
injects the acid into our skin and that
acid causes pain to us few acids are not
found in the living organisms these are
mineral acids as these are formed from
minerals found in the nature as these
are not formed inside any living thing
mineral acid is also called an inorganic
acid for example the sulfuric acid or h2
so4 and nitric acid or hno3
etc are all the examples of mineral
acids the mineral acids are not found in
the living things does that mean it is
harmful for living things are useless to
us no mineral acids are useful in many
ways they are used in many industries
for example the sulfuric acid is often
called the king of chemicals as it is
very useful it is used in manufacturing
car batteries medicines artificial silk
etc you know sulfuric acid is also used
to produce fertilizer called super
phosphate
not only sulfuric acid few other acids
are also used to make different
fertilizers like the nitric acid is used
to make ammonium nitrate hydrochloric
acid is used in the cleaning processes
from cleaning sink to cleaning the huge
spoiler in the factory it is very useful
nitric acid is another common mineral
acid as we have learnt earlier it is
used to make fertilizers it is also used
by goldsmith to clean gold and silver
ornaments nitric acid is heavily used in
making explosives like TNT nitroglycerin
etc these explosives are used in
construction of dams kennels or in
different mineral mines as it can cause
some damages to is there anything that
can be done to stop harmful effects of
acid what can be done about acid
decaying teeth or making soil baron
yes while we are learning about acid
let's learn about another substance
which is the enemy of acid and it is
base acid and base are like snake and
Mongoose the base cancels the acid that
is base can prevent or stop acid so what
is the base base is also around us in
our daily life just like the acid is
bases Peter in taste and feel soapy when
mixed with water and rubbed between the
fingers and when any substance has these
properties we say that substance has
basic nature for example soap baking
soda etc have basic nature
so base is a substance which is exactly
opposite of acid
so whenever acid is causing a problem we
introduced base to stop the acid for
example if the acidity of soil increases
somehow like for example because of acid
rains we add quicklime to the soil to
reduce acidity too much base in the soil
is also bad so we add organic
fertilizers which produce organic acids
to oppose the base thus base and acid
oppose each other hence we can use one
of them to cancel the other whenever
necessary
what is the use of base base is used in
many ways in agriculture
first of all base is used to decrease
the acidity of soil to make it fertile
again generally slake lime which is
calcium hydroxide is used for this slate
lime is also used to make pesticides
bases like ammonium hydroxide is used to
make fertilizers slake lime is also used
in construction for making colors paints
etc you know few bases are used in
medicine for example magnesium hydroxide
is used as an antacid or elective even
few easily available basic substances
like the baking portal lime etc can be
used to bring relief in acidity caustic
soda is one of the most useful base it
is used in paper textile industry and it
is also used in manufacturing soap
detergents etc the strong bases like the
sodium hydroxide etc are also used in
metal industry especially for extracting
metals from the minerals
besides all these bases are heavily used
in alkaline cells food processing etc
now you may wonder are there substances
which are neither acidic nor basic yes
and it is a very common one any guesses
the water we drink is neither acidic nor
basic we say water is a neutral
substance
apart from water there are many
substances which are neither acidic nor
basic for example the common salt which
is sodium chloride and the sugar which
we use daily is also neutral now let us
compare acid with the base what is an
acidic substance acid TSR as it changes
the color of litmus paper from blue to
red and most of the acids are soluble in
water and a solution can carry
electricity and what are the
characteristics of basic substances a
base tastes bitter base fields soapy if
we rub it between two fingers the base
changes color of litmus paper from red
to blue and most of the bases are not
soluble in water that is they are
insoluble in water but the solution of
base can carry electricity
water neutral substances substances
which are neither acidic nor basic in
nature are neutral substances so that
was all about acid and bases bye bye
children