- Introduction
- Rest time! Have fun
- Physics
- Chemistry
- BIOLOGY
- Reaching the age of Adolescence
- CROP PRODUCTION AND MANAGMENT
- Cells : The basic structural unit of life
- Nutrition in human beigns
- RESPIRATION IN HUMAN BEIGNS
- TRANSPORTATION IN HUMAN BEIGNS
- excretory system in human beigns
- NERVOUS SYSTEM
- PHOTOSYNTHESIS
- Respiration in plants
- REPRODUCTION IN PLANTS
- MOVEMENTS IN PLANTS
- Forest our lifeline
- WASTE WATER STORY
- WEATHER,CLIMATE AND ITS ADAPTATION .
- Reaching the age of Adolescence
- Model tests
- Animation time
ACIDS BASES AND SALTS
acids,bases and salts
Introduction
Most of us think that acids are harmfull but not all acids we would learn everything about acids , bases and salts there concentrations everything in this lesson with some activities also .
Acids
They are sour in taste .
For example - lemon has citric acid
tamrind has tartaric acid
Most of them but not all are soluble in water
They are good conductors of electricity
These were some of the properties of acids now we will see types of acids
Types of acids
There are two types of acids they are namely
Organic acids
Inorganic acids
Organic acids
These acids contain -COOH function group.
For example - acetic acid
oxalic acid
citric acid
Inorganic acids
These acids are capable of forming hydrogen ions when dissolved in water.
They are also called mineral acids.
For example- hydrochloric acid
nitric acid
sulphuric acid
Uses of acids
Sulphuric acid
It is known as oil of vitrol as it is used in many ways.
It is used in car batteries.
Hydrochloric acid
To make glue and glucose.
To make arificial silk.
Nitric acid
To make explosures .
To make fertilizers .
Acetic acid
To preserve beetroot and onion.
Used in vinegar.
Bases
They are bitter in taste and soapy to feel .
Alkalis
Soluble bases are known as alkalis .
All alkalis are bases but all bases are not alkalis
For example- magnesium hydroxide is a alkali also a base but alluminium hydroxide is a base but not an alkali .
Indicators
All acids and bases cannot be tested by tasting or touching so they are special
substances which indicate the substance is acidic or basic mainly through colour change these substances are indicators
Types of indicators
there are two types of indicators namely
natural indicators
for examples- litmus (from lichen)
turmeric
red cabbage
hibuscus
artificial indicators
for example - phenolphtalin
methly orange
Nuetral substances
they are niether acidic nor basic .
Some acids and bases and there formulas
hydrochloric acid HCl
sulphuric acid H2SO4
nitric acid HNO3
acetic acid CH3COOH
carbonic acid H2CO3
perchloric acid HClO4
phosphoric acid H3PO4
sodium hydroxide NaOH
pottasium hydroxide KOH
calcium hydroxide Ca(OH)2
magnesium hydroxide Mg(OH)2
ammonium hydroxide NH4OH
alluminium hydroxide Al(OH)3
iron hydroxide Fe(OH)3
Now we know formulas of some acids now we will move on to nuetrilization
Nuetrilization
The process in which acid and base mix up to form a new substance called salt and water with total different properties these salts are niether acidic nor basic these are nuetral .
ACID + BASE = SALT + WATER
Some examples
When we are suffering with acidity because of hydrochloric acid we take ant acid which is magnesium hydroxide
Whenever ant bites us it injects formic acid we nuetrilize it by applying baking soda to reduce the pain .
I think that now you know what is nuetralization , now we will learn it more deeply
We know that
ACID + BASE = SALT + WATER
For example we have
HCl acid and NaOH base
HCl + NaOH = Salt + H20
water has 2 molecules of hydrogen and 1 molecule of oxygen so we should remove these off from HCl and NaOH
we remove 1 molecule H from HCl so the remaining part is Cl we dont remove any oxygen because HCl has no oxygen . In NaOH we remove 1 molecule of H and 1 molecoule of O2 so the remaining part is Na
Now we have to join the left outs of bases and acids by the following steps
first take base's remaing part that is Na then take acids which is Cl then mix it up
Na+ + Cl -
the product we get is NaCl which is Sodium chloride
One more example
HCl + KOH
Remove 2 molecules of H and 1 molecules of O2
we get the salt as KCL which is pottasium chloride
Now we will see some therios of arrehinius and brownsted- lowry
Therio of
ARREHINIUS
He said that
acids donate H+
bases donate OH-
BROWNSTED-LOWRY
acids donate H+
bases donate OH-
Now we should know the strength of acid and bases for that we should know what is log
In mathematics, the logarithm of a number to a given base is the power or exponent to which the base must be raised in order to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 3 is the power to which ten must be raised to produce 1000: 103 = 1000. The logarithm of x to the base b is written logb(x) or log(x) when the base b is implicit.
Logarithms reduce multiplication to addition, and exponentiation to products by the formulas:
logb(x · y) = logb(x) + logb(y) and
logb(xp) = p logb(x).
10 log = 1
pH = -log[H+]
The above formula is find the strength of acids which we will use later
To know the strength we should know its concentration of the solutions
By concentration of solution we can find its pH
We know that pH =-log[H+]
For example we take -
Find the pH of HCl of concentration 10 -3
first split it into ions
i.e. HCl = H+ + Cl-
Now we will use the formula
pH = -log [H+]
=-log [ 10-3]
=10log3
=1*3
=3
To find strength of bases we use pOH
pH + pOH = 14
pOH = -log[OH-]
SOLVED EXAMPLES
1. pH of HNO3 concentration is 0.00001 M/l
Ans HNO3 = H* + NO3-
pH = -log[H*]
= -log[0.00001 M/l]
= -log[10-5 ]
= 5 log 10
=5
2.pH of HCl of 10-3 M/l
Ans HCl = H* + Cl-
pH = -log[H*]
= -log[10-3]
= 3 log 10
= 3
3.pH of NaOH of 10-2 M/l
Ans NaOH is a base so find we should find its pOH
NaOH = Na* + Cl-
pOH= -log[OH-]
= -log[ 10-2]
= 2 log 10
= 2
We know that
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
= 12
4. pH of Ca(OH)2 of 10-2 M/l
Ans Ca(OH)2 = Ca2* + 2OH-
pOH = -log[OH-]
= -log[10-2*2]
= -log[10-4]
= 4 log 10
= 4
pH = 14 - 4
= 10
5. pH of CH3COOH of 10-6 M/l
Ans CH3COOH = CH3COO- + H*
pH = - log[H*]
= - log[10-6]
= 6 log 10
= 6
6.pH of NaOH of 10-5 M/l
Ans NaOH = Na* + OH-
pOH = -log[OH-]
= -log[10-5]
= 5 log 10
= 5
pH = 14 - 5
= 9
Complete the following nuetrilization reactions
7. KOH + HNO3 = ----------------------- + H20
= KNO3 + H20
8. KNO3 + H20 = ------------ + -----------
= No reaction
9. NaNO3 + H2O = ------------ + ---------------
= No reaction
10.CH3COOH +NaOH = ---------------- + --------------------
= CH3COONa + H20
Introduction
Most of us think that acids are harmfull but not all acids we would learn everything about acids , bases and salts there concentrations everything in this lesson with some activities also .
Acids
They are sour in taste .
For example - lemon has citric acid
tamrind has tartaric acid
Most of them but not all are soluble in water
They are good conductors of electricity
These were some of the properties of acids now we will see types of acids
Types of acids
There are two types of acids they are namely
Organic acids
Inorganic acids
Organic acids
These acids contain -COOH function group.
For example - acetic acid
oxalic acid
citric acid
Inorganic acids
These acids are capable of forming hydrogen ions when dissolved in water.
They are also called mineral acids.
For example- hydrochloric acid
nitric acid
sulphuric acid
Uses of acids
Sulphuric acid
It is known as oil of vitrol as it is used in many ways.
It is used in car batteries.
Hydrochloric acid
To make glue and glucose.
To make arificial silk.
Nitric acid
To make explosures .
To make fertilizers .
Acetic acid
To preserve beetroot and onion.
Used in vinegar.
Bases
They are bitter in taste and soapy to feel .
Alkalis
Soluble bases are known as alkalis .
All alkalis are bases but all bases are not alkalis
For example- magnesium hydroxide is a alkali also a base but alluminium hydroxide is a base but not an alkali .
Indicators
All acids and bases cannot be tested by tasting or touching so they are special
substances which indicate the substance is acidic or basic mainly through colour change these substances are indicators
Types of indicators
there are two types of indicators namely
natural indicators
for examples- litmus (from lichen)
turmeric
red cabbage
hibuscus
artificial indicators
for example - phenolphtalin
methly orange
Nuetral substances
they are niether acidic nor basic .
Some acids and bases and there formulas
hydrochloric acid HCl
sulphuric acid H2SO4
nitric acid HNO3
acetic acid CH3COOH
carbonic acid H2CO3
perchloric acid HClO4
phosphoric acid H3PO4
sodium hydroxide NaOH
pottasium hydroxide KOH
calcium hydroxide Ca(OH)2
magnesium hydroxide Mg(OH)2
ammonium hydroxide NH4OH
alluminium hydroxide Al(OH)3
iron hydroxide Fe(OH)3
Now we know formulas of some acids now we will move on to nuetrilization
Nuetrilization
The process in which acid and base mix up to form a new substance called salt and water with total different properties these salts are niether acidic nor basic these are nuetral .
ACID + BASE = SALT + WATER
Some examples
When we are suffering with acidity because of hydrochloric acid we take ant acid which is magnesium hydroxide
Whenever ant bites us it injects formic acid we nuetrilize it by applying baking soda to reduce the pain .
I think that now you know what is nuetralization , now we will learn it more deeply
We know that
ACID + BASE = SALT + WATER
For example we have
HCl acid and NaOH base
HCl + NaOH = Salt + H20
water has 2 molecules of hydrogen and 1 molecule of oxygen so we should remove these off from HCl and NaOH
we remove 1 molecule H from HCl so the remaining part is Cl we dont remove any oxygen because HCl has no oxygen . In NaOH we remove 1 molecule of H and 1 molecoule of O2 so the remaining part is Na
Now we have to join the left outs of bases and acids by the following steps
first take base's remaing part that is Na then take acids which is Cl then mix it up
Na+ + Cl -
the product we get is NaCl which is Sodium chloride
One more example
HCl + KOH
Remove 2 molecules of H and 1 molecules of O2
we get the salt as KCL which is pottasium chloride
Now we will see some therios of arrehinius and brownsted- lowry
Therio of
ARREHINIUS
He said that
acids donate H+
bases donate OH-
BROWNSTED-LOWRY
acids donate H+
bases donate OH-
Now we should know the strength of acid and bases for that we should know what is log
In mathematics, the logarithm of a number to a given base is the power or exponent to which the base must be raised in order to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 3 is the power to which ten must be raised to produce 1000: 103 = 1000. The logarithm of x to the base b is written logb(x) or log(x) when the base b is implicit.
Logarithms reduce multiplication to addition, and exponentiation to products by the formulas:
logb(x · y) = logb(x) + logb(y) and
logb(xp) = p logb(x).
10 log = 1
pH = -log[H+]
The above formula is find the strength of acids which we will use later
To know the strength we should know its concentration of the solutions
By concentration of solution we can find its pH
We know that pH =-log[H+]
For example we take -
Find the pH of HCl of concentration 10 -3
first split it into ions
i.e. HCl = H+ + Cl-
Now we will use the formula
pH = -log [H+]
=-log [ 10-3]
=10log3
=1*3
=3
To find strength of bases we use pOH
pH + pOH = 14
pOH = -log[OH-]
SOLVED EXAMPLES
1. pH of HNO3 concentration is 0.00001 M/l
Ans HNO3 = H* + NO3-
pH = -log[H*]
= -log[0.00001 M/l]
= -log[10-5 ]
= 5 log 10
=5
2.pH of HCl of 10-3 M/l
Ans HCl = H* + Cl-
pH = -log[H*]
= -log[10-3]
= 3 log 10
= 3
3.pH of NaOH of 10-2 M/l
Ans NaOH is a base so find we should find its pOH
NaOH = Na* + Cl-
pOH= -log[OH-]
= -log[ 10-2]
= 2 log 10
= 2
We know that
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
= 12
4. pH of Ca(OH)2 of 10-2 M/l
Ans Ca(OH)2 = Ca2* + 2OH-
pOH = -log[OH-]
= -log[10-2*2]
= -log[10-4]
= 4 log 10
= 4
pH = 14 - 4
= 10
5. pH of CH3COOH of 10-6 M/l
Ans CH3COOH = CH3COO- + H*
pH = - log[H*]
= - log[10-6]
= 6 log 10
= 6
6.pH of NaOH of 10-5 M/l
Ans NaOH = Na* + OH-
pOH = -log[OH-]
= -log[10-5]
= 5 log 10
= 5
pH = 14 - 5
= 9
Complete the following nuetrilization reactions
7. KOH + HNO3 = ----------------------- + H20
= KNO3 + H20
8. KNO3 + H20 = ------------ + -----------
= No reaction
9. NaNO3 + H2O = ------------ + ---------------
= No reaction
10.CH3COOH +NaOH = ---------------- + --------------------
= CH3COONa + H20