Is Matter Around Us Pure Flashcards
What is a pure substance?
A substance which consists of only a single type of constituent particle is called a pure substance.
What is an element?
An element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions.
What is a mixture?
A mixture is substance which consist of two or more elements or compounds not chemically combined together.
What are the two types of mixtures?
Homogeneous mixtures and heterogeneous mixtures
What is a homogeneous mixture?
A mixture in which the constituents are distributed throughout without any clear boundary of separation.
What is a heterogeneous mixture?
A mixture that does not have uniform composition and it has a visible boundary of separation between its constituents.
What are the properties of mixtures?
1) A mixture can be separated into its constituents by physical processes
2) A mixture shows all the properties of its constituents present in it
3) Energy is neither given out nor absorbed during the preparation of mixtures
4) The composition of mixtures is variable
5) Mixtures does not have fixed melting and boiling points
What are the differences between homogeneous and heterogeneous mixtures?
Homogeneous
1) The constituents are uniformly distributed throughout
2) There is no visible boundary of separation between the constituent
3) The constituent cannot be separated easily, special methods are required for this purpose
Heterogeneous
1) The constituents are not distributed uniformly
2) There are visible boundary of separation
3) Constituents can be easily separated by simple methods
What is a compound?
It is a substance made up of two or more elements combined together in a fixed proportion by mass.
What are the properties of compounds?
1) A compound not be separated into its constituents by physical processes
2) Properties of compounds are entirely different from that of its constituents
3) Energy is either given out or absorbed during the preparation of compounds
4) The composition of compounds is fixed
5) Compounds have fixed melting and boiling point.
What is a solution?
It’s a homogeneous mixture of two or more substances.
What is tincture iodine?
A solution of iodine in alcohol
What is solvent?
The component of solution that dissolves the other component in it.
What is solute?
The component of the solution that is dissolved in the solvent.
What are the properties of solutions?
1) Solution is a homogeneous mixture.
2) The particles of solution are smaller than 1 nanometer in diameter
3) The solution do not scatter the beam of light, so the path of the light is not visible.
4) The solutions are stable, that is the solute particles do not settle down when left undisturbed.
5) The solutions cannot be seperated by the process of filteration.
Define the concentration of a solution.
It is the amount of solute present in a given amount of solution.
Concentration of solution =
Mass of solute/Mass of solution ×100
Formula to find the mass of solution
Mass of solution = Mass of solvent + mass of solute
What is suspension?
It is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium.
What are the properties of suspension?
1)Suspension is a heterogeneous mixture.
2) The particles of suspension are greater than 100 nanometer in diameter
3) The suspension scatters the beam of light, so the path of the light is visible.
4) The suspension is unstable, that is the solute particles settle down when left undisturbed.
5) The suspension can be seperated by the process of filteration.
What are colloids?
It is a mixture that is actually heterogeneous but appears to be homogeneous as the particles are uniformly spread throughout the solution
What are the properties of colloids?
1) Colloids is a heterogeneous mixture.
2) The particles of colloids are greater than solution and smaller than suspension
3) The colloids scatters the beam of light, so the path of the light is visible.
4) The colloids are stable, that is the solute particles do not settle down when left undisturbed.
5) The colloids can not be seperated by the process of filteration.
What are the differences between physical change and chemical change?
Physical change
1) no new substances formed in a physical change
2) it is a temporary change
3) it is easily reversible
4) the mass of a substance does not alter in physical change
Chemical change
1) new substances formed in a chemical change
2) it is a permanent change
3) it is not easily reversible
4) the mass of a substance does alter in chemical change
What are the differences between physical change and chemical change?
Physical change
1) no new substances formed in a physical change
2) it is a temporary change
3) it is easily reversible
4) the mass of a substance does not alter in physical change
Chemical change
1) new substances formed in a chemical change
2) it is a permanent change
3) it is not easily reversible
4) the mass of a substance does alter in chemical change
