Solutions 1 Flashcards
define solutions
Solutions are homogeneous mixtures of two or more than two
components. By homogenous mixture we mean that its composition
and properties are uniform throughout the mixture.
what is solvent, solute
Generally, the
component that is present in the largest quantity is known as solvent.
Solvent determines the physical state in which solution exists. One or
more components present in the solution other than solvent are called
solutes.
Binary solutions are those solutions with contain only 2 components.
Name some gaseous solutions
Solid in Gas
Camphor in nitorgen gas
Liquid in Gas
Chloroform mixed with nitrogen gas
Gas in gas
mixture of nitrogen and oxygen
name some liquid solutions
Solid in liquid
glucose dissolved in water
liquid in liquid
ethanol dissolved in water
gas in liquid
oxygen dissolved in water
name some solid solutions
Soldi in solid
Copper dissolved in gold
Liquid in solid
amalgam of mercury with sodium
Hg- liq
Na- solid
Gas in solid
solution of Hydrogen in palladium
define solubility
Solubility of a substance is its maximum amount that can be dissolved
in a specified amount of solvent at a specified temperature. It depends
upon the nature of solute and solvent as well as temperature and
pressure.
The solution which is in dynamic equilibrium
with undissolved solute is the saturated solution and contains the
maximum amount of solute dissolved in a given amount of solvent.
Thus, the concentration of solute in such a solution is its solubility.
solids in liquid: how does solubility depend on nature of solvent and solution
Every solid does not dissolve in a given liquid. While sodium chloride
and sugar dissolve readily in water, naphthalene and anthracene do
not. On the other hand, naphthalene and anthracene dissolve readily in
benzene but sodium chloride and sugar do not.
It is observed that
polar solutes dissolve in polar solvents and non polar solutes in nonpolar solvents. In general, a solute dissolves in a solvent if the
intermolecular interactions are similar in the two or we may say like
dissolves like.
when is equilibrium reached between solid solute and liquid
When a solid solute is added to the solvent, some solute dissolves
and its concentration increases in solution. This process is known as
dissolution. Some solute particles in solution collide with the solid solute
particles and get separated out of solution. This process is known as
crystallisation. A stage is reached when the two processes occur at the
same rate. Under such conditions, number of solute particles going
into solution will be equal to the solute particles separating out and
a state of dynamic equilibrium is reached.
what are saturated solution and unsaturated solutions
a solution in which no more solute can be dissolved at the same
temperature and pressure is called a saturated solution. An
unsaturated solution is one in which more solute can be dissolved at
the same temperature.
explain the effect of temperatuee on solutbility of solids in liquids
The solubility of a solid in a liquid is significantly affected by temperature
changes. Consider the equilibrium represented by equation 2.10. This,
being dynamic equilibrium, must follow Le Chateliers Principle. In
general, if in a nearly saturated solution, the dissolution process is
endothermic (∆sol H > 0), the solubility should increase with rise in
temperature and if it is exothermic (∆sol H < 0) the solubility should
decrease. These trends are also observed experimentally.
what is the effect of pressure on the solubility of solids in liquids
Pressure does not have any significant effect on solubility of solids in
liquids. It is so because solids and liquids are highly incompressible
and practically remain unaffected by changes in pressure.
how does solubility of gas in liquid depend on the gas ?
Some gases like H2, N2 and O2 dissolve in water only to a small extent whereas CO2, HCl, NH3 are highly soluble.
Many gases dissolve in water. Oxygen dissolves only to a small extent
in water. It is this dissolved oxygen which sustains all aquatic life. On
the other hand, hydrogen chloride gas (HCl) is highly soluble in water.
how does solubility of gas in liquid depend on temperature
dissolution of gas in liquid is exothermic
so with increase in temperature the solubility decreases
Solute+ OSlvent <—-> solution + heat
why do aquatic species prefer cooler water?
Aquatic species prefer cooler waters due to greater amount of dissolved oxygen in cooler temperatures than warmer. As temperature rises, the dissolved oxyen decreases, b/c solubility of gases ecrease with increase in temperature.
how does solubility of gas in liquid depend on pressure
The solubility of gases increase with increase of pressure.
