Q.(1).Define the following:
Ans: (a).Pure substances: A pure substance is the
substance that is made by same kind of atoms or
molecules. E-g: Elements and compunds
(b).Elements: A element is the basic form of matter
that can’t be broken down into simpler
substances.E-g: Aluminium,Gold,Silver etc.,
(c). Compunds: A compound is a substance that is
formed by the combination of two or more
elements in a fixed proportion by mass.E-g: Water
is a compound of hydrogen and oxygen which is
formed by or is a ratio of 1:8 by mass.
(d).Mixture: When two or more pure form of matter
are mixed in any proportion they form mixtures.Eg:Air is a mixture of nitrogen,oxygen,carbon
dioxide etc.,
(Q.)2. With proper examples describe different
types of mixtures.
Ans: (1) Homogeneous mixture: A mixture which
has uniform composition throughout is called
homogeneous mixture.E-g:Sugar or salt in water.
(2).Heterogeneous mixture: A mixture which
doesn’t have uniform composition throughout is ca
lled heterogeneous mixture.E-g:Oil or sand in
water.
Q.3. Differentiate between mixture and
compounds.
Ans: Pg.No: 26.
Q.4. What is a solution?
Ans: A solution is a homogeneous mixture of two
or more substances.
Q.5. What are the components of a solution?
Ans: A solution has a solvent and a solute as its
components.The component which is dissolved in
the solvent is solute.The component of the solution
that dissolves the other component in it, is called
solvent.
Q.6.What are the properties of a solution?
Ans.1.A solution is a homogeneous mixture.
2. The particles of a solution are smaller than
nanometer(i.e 10−9 m) in diameter).So they cannot
be seen by naked eyes.
3.Due to very small particles size,they don’t scatter
a beam of light passing through the solution.So the
path of light is not visible in a solution.
4. The solute particles cannot be separated from
the mixture by the process of fitration.
Q.7.Explain the classification of solution on the
basis of the physical states of the solute and
solvent.
Ans:
solutions
Examples
Solid in solid
Brass and bronze
Solid in liquid
Sugar in water
Solid in gas
air,smog,smoke
Dust particles in
Liquid in solid
cheese,butter
Liquid in liquid
Alcohol in water
Liquid in gas
Moisture in water
Gas in solid
Hydrogen in palladium
Gas in liquid
Aerated water
Gas in gas
Air
Q.8.What is saturated solition?
Ans: When no more solute can be dissolved in a
solution, at a given temperature, it is called a
saturated solution.
Q.9.What is solubility?
Ans: The amount of solute present in a saturated
solution at a given temperature is called solubility.
Q.10.What is the concentration of a solution?
Ans : The concentration of a solution is the amount
of solute present in a given amount of solution or
the amount of solute dissolved in a given mass or
volume of solvent.
Therefore the concentration of a solution = Amount
of solute
Amount of solution
Q.11.Define unsaturated solution.
Ans: If the amount of solute contained in a solution
is less than the saturation level,it is called
unsaturated solution.
Q.12.Mention two ways to express the
concentration of a solution.
Ans: