SS Academy Rajapuram
Acids, Bases and Salts
→
Any substance that has a sour taste and
turns blue litmus
to red is called
an ‘acid’.
→ Any substance
that has a bitter taste and soapy in nature
that turns red litmus to blue is called a base.
→
We use natural and chemical
indicators to test for acids
and bases.
→
Acid-base indicators are dyes or mixtures
of dyes that are
used to indicate the presence of acids and bases.
→ When acids and bases react with each other, their respective salts and water are formed.
This chemical reaction is called
neutralization.
→ The acidic
nature of a substance is due to the formation of H+ (aq) ions in the solution. The formation of OH–
(aq) ions in the solution are responsible for the
basic nature of a substance.
→ Some
substances whose odour changes in acidic or basic media are called
Olfactory indicators.
→ When a base
reacts with a metal with the evolution of hydrogen gas, a
salt is formed.
→ When an acid
reacts with a metal carbonate or metal hydrogen
carbonate gives the corresponding salt, carbon
dioxide gas and water.
→ Metallic oxides react with acids to give salt and water. Metallic oxides are basic in nature.
→ Non-metallic oxides are acidic in nature.
→ Acidic and basic solutions in water conduct electricity because they produce hydrogen ions and
hydroxide ions respectively.
→ Acid
solutions have ions and the electric current is carried through the movement
of ions in the solution.
→ In glucose and alcohol ions are
absent.
→ Dissolving bases in water produces
hydroxide (OH–) ions.
→ Bases that are soluble in water are called alkalis.
→ The process of
dissolving an acid or a base in water is an
exothermic process.
→ Mixing an acid or base with water results
in dilution.
→ Strong acids
are completely ionized whereas weak acids are
partially Ionized.
→ Strong bases release more OH– ions in water, whereas weak
bases release fewer OH– ions
in water.
→ The strength of an acid or an alkali can be tested by using a scale called the pH scale (0-14) which
gives the measure of hydrogen ion concentration in a solution.
→ A neutral
solution has a pH of 7, while an acidic solution has a pH less than 7 and a basic solution has a pH of more than 7.
→ A mixture of several indicators is called a Universal
indicator.
→ pH scale ¡s used for measuring hydrogen
ion
concentration in a solution.
→ Living
beings carry out their metabolic
activities within an optimal pH range.
→ Our body works within
the pH range of 7.0 to 7.8.
→ When the pH of rainwater is less than 5.6, it is called
acid
rain.
→ Mixing concentrated acids or bases with water is a highly exothermic process.
→ Acids and
bases neutralize each other to form corresponding salts and water.
→ The water of
crystallization is the fixed number of water
molecules chemically attached to each formula unit of salt in its crystalline form.
→ Antacids
are the mild bases used to control the stomach
pain caused due to indigestion.
→ Magnesium
hydroxide is known as the ‘milk of magnesia’.
→ Tooth decay
starts when the H of the mouth is lower than
5.5.
→ The atmosphere
of Venus is made ¿p of thick white and yellowish clouds of
sulphuric acid.
→ Salts are electrically neutral.
→ Beds of rock salts are formed when seas of bygone
ages
dried up.
→ Sodium
hydrogen carbonate is used in soda acid fire
extinguishers.
→ Washing soda is used in the manufacture of borax.
→ Salts have various
uses in everyday
life and in industries.
→ Plaster of
Paris (CaSO4, 6H20) is used for making toys,
materials for decoration and for making
surfaces smooth.
→ Indicator: A
special substance that gives different colours
in acidic, and basic media.
→ Acid: ‘Acid’
is a word derived from the Latin word ‘Acidus’. It means sour. Usually, we call any substance that has a sour taste.
→ Base: The substance that has
a bitter taste and is slippery
to touch.
→ Red Litmus: A
red coloured indicator used to test the presence of basic nature in a substance.
→ Blue
Litmus: A blue coloured indicator used to test the presence of acidic nature in a substance.
→ Phenolphthalein and Methyl
Orange: The synthetic (chemical) indicators to find the presence of acids and bases.
→ Salts: A substance that is
formed as a result
of the
neutralization reaction
between an acid and a base.
→
Neutralization: When acids and bases react, salt and water are formed. This chemical reaction is known as neutralization.
→ Guard tube: A drying
tube used in experiments.
→ Hydronium ion: H3O+ ion.
→ Alkali: A base that is
soluble in water is called alkali.
→ Strong acid:
Acid that gives more H30+ ions (They are ionized completely).
→
Strong Base: Base that
gives more OH– ions in water.
→ Universal indicator: It is a mixture of several indicators.
→ pH Scale: A scale for measuring hydrogen ion
concentration in a solution. pH = – log10 (H+)
→ Potenz: A scale
for measuring hydrogen ion concentration in
a solution is called the pH scale. The ‘P’s in pH stands for Potenz.
In German ‘Potenz’
is power.
→ Antacids: A
mild base used to get rid of pain and irritation caused due to indigestion of food.
→ Tooth decay:
Corrosion of tooth due to the degradation of
sugar and food particles
remaining in the mouth.
→ Family of
Salts: Salts having the same positive or negative radicals belong to a family
called a family of salts.
→ Common Salt or Table Salt: Sodium Chloride
Salt (NaCl).
→ Bleaching
Powder: The action of chlorine on dry slaked
lime.
→ Baking Soda:
Sodium bicarbonate salt is used in the kitchen for making tasty and crispy pakoras.
→ Washing Soda: Sodium carbonate salt is used in washing
clothes, etc.
→
Hydrated Salt: Salt which contains water.
→ The water of
crystallization: It is the fixed number of water
molecules chemically attached to each formula unit of salt in its crystalline form.
→ Plaster of
Paris: On heating gypsum at 373 K it loses water molecules and becomes Calcium Sulphate hemihydrate called
Plaster of Paris.
→ Olfactory
indicators: The substances whose odour changes in acidic or basic
media.
→ Litmus solution: A natural indicator
extracted from certain
lichens.
→
Lichen: Rock Moss.
→
Endothermic reaction: A chemical
reaction in which heat
is absorbed.
→
Exothermic reaction: A chemical reaction
in which heat is
evolved.
→ Aqueous
Solution: The solution in which the solvent is
water.
→ The
concentration of a Solution: The amount of solute present per unit volume
or per unit mass of the solution.
→ Weak acids: Acids that
give fewer (less) H3O+ ions (They
are not ionized completely).
→
Weak bases: Bases that give fewer (less) OH– ions in
water.
→
Saturated solution: The solution in which the amount of
solute dissolved is equal to solubility.
→
Unsaturated solution: The solution in which solute
is less
than the solvent.
→ Supersaturated
solutIon: The solution in which the solute
dissolved is more than its solubility.
→ Acid rain: When
the pH of rainwater is less than 5.6, it is
called acid rain.
→ Rock Salt:
Deposits of seawater (solid salt) are changed to large brown crystals called
Rock salt.
→
Dry slaked lime:
Ca (OH)2 (i.e.,)
Calcium Hydroxide.
→ Brine solution: An aqueous
solution of common
salt.
→
Anode: A positive electrode.
→
Cathode: A negative electrode.
→
Quick lime: CaO (Calcium Oxide).
→
Achara Nagarjuna (AD 931):
Acharya Nagarjuna
was born In AD 931 in Gujarat (India). He was an alchemist.
He knew an artel transmuting base metals to look
like gold.
He was a
metallurgist and chemist. He was very famous for his book Rasevada’ Which deals with Mercury compounds.
He discussed the extraction of costly Metairie
gold, alive;
etc. In bis wrItings.
→ JFW Adolf Von Baeyer (1835
– 1917):
Johann Friedrich
Wilhelm Adoli Von Baeyer was born on October 31, 1835 In Berlin (Germany).
He was
interested In chemical experiments. He found a new double salt of copper.
He studied Methyl Chloride, Uric acid, Indigo, etc. He discovered Indole.
His ‘Baeyer
strain theory of the Carbon iingW Is very famous. He received the Nobel Prize In
1905.
