Solutions
Solution
It is a homogeneous mixture of two or more
chemically non-reacting substances whose Concept Ladder
composition can be changed within certain limits. A solution which contains
A solution is regarded as a singular phase having as much solute as it
more than one component. can dissolve at a given
A solution which contains two components is temperature is called a
known as binary solution. saturated solution.
A solution which contains
The component which is present in smaller
lesser solute than the
quantities is called the solute and the other
amount of solute if
which present in larger amount is known as the
can dissolve is called
solvent.
unsaturated solution.
The below table shows the list of solutions and
their examples.
Types of Solutions
Solutions of Solids in Liquids
y It is a solution which still in contact with Concept Ladder
excess of solute. A solution which contains
y The solubility of the solute is defined as the more solute than the
amount of solute dissolved per 100 g of solvent amount of solute it can
at a specific temperature for a saturated dissolve at a particular
solution. temperature is called a
Solutions
y For exothermic substances such as KOH, CaO, super saturated solution.
Ca(OH)2, M2CO3, M2SO4 etc.,
1.
, solubility is inversely proportional to
temperature. (M = Alkali metals) Rack your Brain
y For endothermic substances such as NaCl,
KNO3, NaNO2, glucose etc., solubility is directly Why do aquatic species like fish
proportional to temperature. feel more comfortable in the
lakes in winter than in summer?
Solubility of Gases
y Solubility of gases is mostly described in
terms of absorption coefficient, i.e., the
Previous Year’s Questions
volume of the gas (at normal temperature and
pressure), dissolved by unit volume of solvent,
The beans are cooked earlier in
at a specific temperature and 1 atm pressure.
pressure cooker because.
y The solubility factor for a gas in a liquid
[NEET]
depends upon:
(1) Boiling point increases with
1. Temperature
increasing pressure
Solubility have inverse relation with
(2) Boiling point decreases with
temperature as dissolution of a gas is
increassing pressure
exothermic in most cases.
(3) Extra pressure of pressure
Gas + liquid ⇒ Dissolved gas cooker softens the beans
(4) Internal energy is not lost
∆H = –ve
while cooking in pressure
2. Nature of gas cooker.
The gas which can be easily liquified are
more soluble as they contian higher value
of van der Waal’s force of attraction. For
Concept Ladder
example, SO2 and CO2 are more soluble in
water than O2, N2 and H2. Solubility of gases in
3. Nature of solvent liquids decreases with
Gases which can be ionized in aq. solution rise in temperature.
are more soluble in H2O as compared to When dissolved, the gas
the other solvents. molecules are present
4. Pressure of the gas (Henry’s law) in liquid phase and the
This law states that the solubility of a gas process of dissolution can
in a given volume of liquid at constant be considered similar to
temperature is directly proporitonal to condensation and heat is
the pressure of the gas. evolved in this process. As
m∝P dissolution is an exothermic
process. the solubility
m = KP should decrease with
increase of temperature.
Solutions
2.
, m
or = KH (At constant temperature)
p
Rack your Brain
P = Pressure of gas at equlilibrium with
solution Why does the solubility
m = The mass of gas dissolved by unit of exothermic substances
volume of solvent. decreases with increasing of
Here KH = Henry’s constant (Function of temperatrue?
nature gas)
When solubility is expressed as its mole
fraction (X)
P ∝ X or P = KH X
1
So lub ility ∝
KH
Concept Ladder
To increase the solubility of
CO2 in soft drinks and soda
water, the bottle is sealed
under high pressure.
y Henry’s law is obeyed only when
1. Gas does not dissociate.
2. Pressure is not too high.
3. In solvent, gas is not highly soluble.
4. Temperature is not too low.
5. Gas should be inert.
e.g. NH3 + H2O
NH4OH
Concept Ladder
y The volume of the dissolved gas does not
When air enters the lungs,
depend upon pressure at a particular
partial pressure of oxygen is
Temperature.
high. This oxygen combines
Applications of Henry’s Law: with haemoglobin to form
(1) Soft drinks bottles are sealed at high oxyhaemoglobin. Partial
pressures to increase solubility of CO2 in pressure of O2 in tissues is
water. low. Hence, O2 is released
(2) Sea divers used a mixture of O2 + He from oxyhaemoglobin
to minimize the painful effect by N2 in which is utilised for
decomposition. functions of the cells.
Solutions
3.
, (3) At higher altitudes, breathing becomes
tough as O2 is less available in the air due
to less pressure.
Expression of Concentration of Solution
Solubility
The amount of solute which is dissolved in a
specific amount/volume of solution. It is denoted
by C or S.
Concept Ladder
Weight of solute in gram W Air quality measurement
C or S = or g / L
Volume in litre V are commonly reported in
C= N × E terms of: micrograms per
cubic meter (mg/m3) part
N = Normality of solution, per meilion (ppm) or parts
E = Eqivalent weight of solute per billion (ppb)
Concentration in parts per million (ppm)
When any amount of solute is present in one
million (106) parts of the solution, then it is known
as ppm.
Mass of A
=ppm(A) × 106
Total mass of the solution
Concentration in parts per billion (ppb)
When any amount of solute is present in one
billion (109) parts of the solution, then it is known
as ppb.
Mass of A Previous Year’s Questions
=ppb(A) × 109
Total mass of the solution
Molarity (M) How many grams of concentrated
It is the no. of moles of solute present in one nitric acid solution should be
litre of the solution, and it is denoted by M. used to prepare 250 mL of 2.0 M
y When molarity of a solution is one, it is called HNO3? The concentrated acid is
one molar solution. 70% HNO3. [NEET]
Weight of solute in gram (1) 70.0 g conc. HNO3
M=
Molar mass × Volume in litre (2) 54.0 g conc. HNO3
In case of dilution or mixing, (3) 45.0 g conc. HNO3
M
=1 V1 M
=2 V2 M3 V3 (4) 90.0 g conc. HNO3
M1 V1 + M2 V2 M V − MB VB
MR = or A A
V1 + V2 VA + VB
A → Acid; 1 → So lute (1)
Solutions
B → Base; 2 → So lute (2)
(Both don't react with
each other) 4.
Solution
It is a homogeneous mixture of two or more
chemically non-reacting substances whose Concept Ladder
composition can be changed within certain limits. A solution which contains
A solution is regarded as a singular phase having as much solute as it
more than one component. can dissolve at a given
A solution which contains two components is temperature is called a
known as binary solution. saturated solution.
A solution which contains
The component which is present in smaller
lesser solute than the
quantities is called the solute and the other
amount of solute if
which present in larger amount is known as the
can dissolve is called
solvent.
unsaturated solution.
The below table shows the list of solutions and
their examples.
Types of Solutions
Solutions of Solids in Liquids
y It is a solution which still in contact with Concept Ladder
excess of solute. A solution which contains
y The solubility of the solute is defined as the more solute than the
amount of solute dissolved per 100 g of solvent amount of solute it can
at a specific temperature for a saturated dissolve at a particular
solution. temperature is called a
Solutions
y For exothermic substances such as KOH, CaO, super saturated solution.
Ca(OH)2, M2CO3, M2SO4 etc.,
1.
, solubility is inversely proportional to
temperature. (M = Alkali metals) Rack your Brain
y For endothermic substances such as NaCl,
KNO3, NaNO2, glucose etc., solubility is directly Why do aquatic species like fish
proportional to temperature. feel more comfortable in the
lakes in winter than in summer?
Solubility of Gases
y Solubility of gases is mostly described in
terms of absorption coefficient, i.e., the
Previous Year’s Questions
volume of the gas (at normal temperature and
pressure), dissolved by unit volume of solvent,
The beans are cooked earlier in
at a specific temperature and 1 atm pressure.
pressure cooker because.
y The solubility factor for a gas in a liquid
[NEET]
depends upon:
(1) Boiling point increases with
1. Temperature
increasing pressure
Solubility have inverse relation with
(2) Boiling point decreases with
temperature as dissolution of a gas is
increassing pressure
exothermic in most cases.
(3) Extra pressure of pressure
Gas + liquid ⇒ Dissolved gas cooker softens the beans
(4) Internal energy is not lost
∆H = –ve
while cooking in pressure
2. Nature of gas cooker.
The gas which can be easily liquified are
more soluble as they contian higher value
of van der Waal’s force of attraction. For
Concept Ladder
example, SO2 and CO2 are more soluble in
water than O2, N2 and H2. Solubility of gases in
3. Nature of solvent liquids decreases with
Gases which can be ionized in aq. solution rise in temperature.
are more soluble in H2O as compared to When dissolved, the gas
the other solvents. molecules are present
4. Pressure of the gas (Henry’s law) in liquid phase and the
This law states that the solubility of a gas process of dissolution can
in a given volume of liquid at constant be considered similar to
temperature is directly proporitonal to condensation and heat is
the pressure of the gas. evolved in this process. As
m∝P dissolution is an exothermic
process. the solubility
m = KP should decrease with
increase of temperature.
Solutions
2.
, m
or = KH (At constant temperature)
p
Rack your Brain
P = Pressure of gas at equlilibrium with
solution Why does the solubility
m = The mass of gas dissolved by unit of exothermic substances
volume of solvent. decreases with increasing of
Here KH = Henry’s constant (Function of temperatrue?
nature gas)
When solubility is expressed as its mole
fraction (X)
P ∝ X or P = KH X
1
So lub ility ∝
KH
Concept Ladder
To increase the solubility of
CO2 in soft drinks and soda
water, the bottle is sealed
under high pressure.
y Henry’s law is obeyed only when
1. Gas does not dissociate.
2. Pressure is not too high.
3. In solvent, gas is not highly soluble.
4. Temperature is not too low.
5. Gas should be inert.
e.g. NH3 + H2O
NH4OH
Concept Ladder
y The volume of the dissolved gas does not
When air enters the lungs,
depend upon pressure at a particular
partial pressure of oxygen is
Temperature.
high. This oxygen combines
Applications of Henry’s Law: with haemoglobin to form
(1) Soft drinks bottles are sealed at high oxyhaemoglobin. Partial
pressures to increase solubility of CO2 in pressure of O2 in tissues is
water. low. Hence, O2 is released
(2) Sea divers used a mixture of O2 + He from oxyhaemoglobin
to minimize the painful effect by N2 in which is utilised for
decomposition. functions of the cells.
Solutions
3.
, (3) At higher altitudes, breathing becomes
tough as O2 is less available in the air due
to less pressure.
Expression of Concentration of Solution
Solubility
The amount of solute which is dissolved in a
specific amount/volume of solution. It is denoted
by C or S.
Concept Ladder
Weight of solute in gram W Air quality measurement
C or S = or g / L
Volume in litre V are commonly reported in
C= N × E terms of: micrograms per
cubic meter (mg/m3) part
N = Normality of solution, per meilion (ppm) or parts
E = Eqivalent weight of solute per billion (ppb)
Concentration in parts per million (ppm)
When any amount of solute is present in one
million (106) parts of the solution, then it is known
as ppm.
Mass of A
=ppm(A) × 106
Total mass of the solution
Concentration in parts per billion (ppb)
When any amount of solute is present in one
billion (109) parts of the solution, then it is known
as ppb.
Mass of A Previous Year’s Questions
=ppb(A) × 109
Total mass of the solution
Molarity (M) How many grams of concentrated
It is the no. of moles of solute present in one nitric acid solution should be
litre of the solution, and it is denoted by M. used to prepare 250 mL of 2.0 M
y When molarity of a solution is one, it is called HNO3? The concentrated acid is
one molar solution. 70% HNO3. [NEET]
Weight of solute in gram (1) 70.0 g conc. HNO3
M=
Molar mass × Volume in litre (2) 54.0 g conc. HNO3
In case of dilution or mixing, (3) 45.0 g conc. HNO3
M
=1 V1 M
=2 V2 M3 V3 (4) 90.0 g conc. HNO3
M1 V1 + M2 V2 M V − MB VB
MR = or A A
V1 + V2 VA + VB
A → Acid; 1 → So lute (1)
Solutions
B → Base; 2 → So lute (2)
(Both don't react with
each other) 4.
