Unit 2 Solutions
Solutions are homogeneous mixtures of two or more than two components
Solvent:-Generally, the component that is present in the largest quantity is known
as solvent.
Solvent determines
Solute:-One or morethe physical state
components in which
present in thesolution
solutionexists.
other than solvent are
called solutes.
Generally present in smaller quantity.
Binary solutions:-consisting of two components, Solvent and Solute.
Types of solution:-Depending upon physical state , solutions are categorized in 3 types.
,Types of Solutions
, Expressing Concentration of Solutions
Mass percentage (w/w): Mass % of a component
For example, if a solution is described by 10% glucose in water by mass, it means
that 10 g of glucose is dissolved in 90 g of water resulting in a 100 g solution
Volume𝑜𝑓 𝑡h𝑒 𝑐𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡 𝑖𝑛 𝑡h𝑒 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
Volume % of a component =
Volume percentage (V/V): ×100
𝑇𝑜𝑡𝑎𝑙 volume 𝑜𝑓 𝑡h𝑒 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
• For example, 10% ethanol solution in water means that 10 mL of ethanol is dissolved
in water such that the total volume of the solution is 100 mL.
• Solutions containing liquids are commonly expressed in this unit.
• For example, a 35% (v/v) solution of ethylene glycol, an antifreeze, is used in cars for
cooling the engine
Mass by volume percentage (w/V)
commonly used in medicine and pharmacy. It is the mass of solute dissolved in 100 mL of the
solution.
, Expressing Concentration of Solutions
Parts per million (ppm)=
• Concentration in ppm can also be expressed as mass to mass, volume to volume and
mass to volume.
• A litre of sea water (which weighs 1030 g) contains about 6 × g of dissolved oxygen . Expressed as 5.8 ppm
of sea water.
• The concentration of pollutants in water or atmosphere is often expressed in terms of or ppm.
Mole fraction (x):- Number of moles of the component
Mole fraction of a component =
Total number of moles of all the components
in a binary mixture, if the number of moles of A and B are nA and nB
respectively, the mole fraction of A will be
In a given solution sum of all the mole fractions is unity, i.e.
Solutions are homogeneous mixtures of two or more than two components
Solvent:-Generally, the component that is present in the largest quantity is known
as solvent.
Solvent determines
Solute:-One or morethe physical state
components in which
present in thesolution
solutionexists.
other than solvent are
called solutes.
Generally present in smaller quantity.
Binary solutions:-consisting of two components, Solvent and Solute.
Types of solution:-Depending upon physical state , solutions are categorized in 3 types.
,Types of Solutions
, Expressing Concentration of Solutions
Mass percentage (w/w): Mass % of a component
For example, if a solution is described by 10% glucose in water by mass, it means
that 10 g of glucose is dissolved in 90 g of water resulting in a 100 g solution
Volume𝑜𝑓 𝑡h𝑒 𝑐𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡 𝑖𝑛 𝑡h𝑒 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
Volume % of a component =
Volume percentage (V/V): ×100
𝑇𝑜𝑡𝑎𝑙 volume 𝑜𝑓 𝑡h𝑒 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
• For example, 10% ethanol solution in water means that 10 mL of ethanol is dissolved
in water such that the total volume of the solution is 100 mL.
• Solutions containing liquids are commonly expressed in this unit.
• For example, a 35% (v/v) solution of ethylene glycol, an antifreeze, is used in cars for
cooling the engine
Mass by volume percentage (w/V)
commonly used in medicine and pharmacy. It is the mass of solute dissolved in 100 mL of the
solution.
, Expressing Concentration of Solutions
Parts per million (ppm)=
• Concentration in ppm can also be expressed as mass to mass, volume to volume and
mass to volume.
• A litre of sea water (which weighs 1030 g) contains about 6 × g of dissolved oxygen . Expressed as 5.8 ppm
of sea water.
• The concentration of pollutants in water or atmosphere is often expressed in terms of or ppm.
Mole fraction (x):- Number of moles of the component
Mole fraction of a component =
Total number of moles of all the components
in a binary mixture, if the number of moles of A and B are nA and nB
respectively, the mole fraction of A will be
In a given solution sum of all the mole fractions is unity, i.e.
