Homogeneous and Heterogeneous Mixture
Homogeneous Mixture
1. Those mixtures, which have uniform composition throughout their mass are called homogeneous     mixtures.
2. Homogeneous mixture has only one phase through out its mass.
3. Homogeneous mixture are also known as solution.
4. Examples: Salt and water, Sugar and water.

Heterogeneous Mixture
1. Those mixtures, which do not have uniform composition through their mass are called Heterogeneous     Mixture.
2. Heterogeneous Mixture has more than one phase through out its mass.
3. Heterogeneous Mixture are not solutions.
4. Examples: Rocks, Soil, Food products.

Molecular and Empirical Formula
Molecular Formula
1. Formula which shows the actual number of atoms of each element present in a molecule is called     Molecular Formula.
2. Molecular Formula shows the structure of compound.
3. Two or more compounds cannot have same Molecular Formula.
4. Molecular Formula = n x Empirical Formula.
5. It represents covalent compounds only.

Empirical Formula
1. formula, which shows the relative ratio of atoms of each element present in a molecule, is called     Empirical Formula.
2. Empirical Formula can not show the structure of compound.
3. Two or more compounds can have same Empirical Formula.
4. Empirical Formula = Molecular Formula / n
5. It represent an ionic compound as well as a covalent compound.

Symbol and Formula
Symbol
1. A symbol is an abbreviation for the chemical name of an element and represents only one atom of the     element.
2. It represents one atom of an element.
3. Symbol is written for elements.
4. Examples: Na, Br, Cl, F etc.

Formula
1. Representation of compound in terms of symbols is called formula. It represents one atom of an     element.
2. It represents atoms of same or different elements present in one molecule.
3. It represents an ionic compounds as well as a covalent compound.
4. Examples: H2O, NH3 etc.

Gram and Gram Molecule
Gram
1. The atomic mass of an element expressed in grams is called gram atomic mass.
2. It is associated with element only.
3. It is the mass of one atomic mole.
4. One gram atom of any substance contains 6.02 x 10(23) atoms. (23 is the power of 10).

Gram Molecule
1. Molecular mass of any element or compound expressed in grams is called gram molecule.
2. It is associated with element and compound.
3. It is the mass of one molecular mole.
4. One gram molecule of any substance contains 6.02 x 10(23) atoms. (23 is the power of 10).

Atom and Molecule
Atom
1. It is the smallest particle of an element which can enter into a chemical reaction.
2. It is represented by a symbol of the element.
3. It shows the properties of the element.
4. It retains its identity in a chemical reaction.

Molecule
1. It is the smallest particle of a substance which can exist and show all the properties of the substance.
2. It is represented by a molecular formula of the substance.
3. It shows the properties of the substance.
4. It does not retain its identity in a chemical reaction.

Exothermic and Endothermic Reactions
Exothermic Reaction
1. Those chemical reactions in which heat energy is evolved are called exothermic reactions.
2. In exothermic reactions the enthalpy of products is lower than the reactants. H is therefore negative for     an exothermic reaction.
3. During endothermic reaction, the system becomes colder and net potential energy of substance     increases.
4. The energy is absorbed during these reactions.
5. The temperature of reaction therefore decreases.

Endothermic Reactions
1. Those chemical reactions in which heat energy is absorbed are called endothermic reactions.
2. In endothermic reactions the enthalpy of reactants is lower than the products. H is therefore positive in     endothermic reaction.
3. During endothermic reaction, the system becomes colder and net potential energy of substance     increases.
4. The energy is absorbed during these reactions.
5. The temperature of reaction therefore decreases.

Physical and Chemical Properties
Physical Properties
1. The physical properties of a substance are those characteristics which serve to distinguish it from other     substance but do not deal with its ability to undergo chemical changes.
2. These are related to the physical state of matter.
3. Examples: Formation of ice from water, formation of a magnet from ice etc.

Chemical Properties
1. The chemical properties of a substance indicate the ability of a substance to undergo chemical changes.
2. They are related to the chemical change of a substance.
3. Examples: burning of paper, rusting of iron.

Electrolyte and Non-Electrolyte
Electrolytes
1. Electrolytes conduct electricity in molten or in solution form.
2. These form positive and negative ions when dissolved in water e.g. NaCl form Na+ and Cl- ions when     dissolved in water.
3. Chemical changes occur when electric current is passed through the electrolyte.
4. Generally these are ionic or polar covalent compounds.

Non-Electrolytes
1. Non-electrolytes do not conduct electric current in molten or in solution form.
2. These do not form positive and negative ions when dissolved in water e.g. Urea, sugar, glucose etc.
2. No chemical change occurs in them on passing current.
3. Generally these are non polar covalent compounds.
4. Generally these are non polar covalent compounds.

Acid and Base
Acid
1. Those compounds which provide hydrogen ion (H+) in aqueous solutions are called Acids.
2. An acid is a substance which produces H+ ions in aqueous solution.
3. Acid is a species (a compound or ion) which donates or tends to donate a proton (H+).
4. An acid is a species (molecule or ion) which can accept a pair of electron. An acid is also called an     electrophile (electron loving).
5. They have sour taste.
6. Acid turn blue litmus red methyl orange red.

Base
1. Those compounds, which provides hydroxyl (OH-) ion in aqueous solution, are called bases.
2. A base is a substance, which gives (OH-) in aqueous solution.
3. A base is a species, which accepts or tends to accept a proton.
4. A base is a species (molecule or ion) which can donate a pair of electrons. A base is also called a     nucleophile (Nucleus loving).
5. Bases have bitter taste.
6. Bases turn red litmus to blue, colorless phenolphthalein to pink and methyl orange to yellow.

Ionic and Covalent Bond
Ionic Bond
1. Ionic bond is formed by complete transfer of electrons from one atom to another atom.
2. Ionic bond is always formed between different atoms. E.g. NaCl, CaCl2.
3. In ionic bond atoms have very large electro-negativity and ionization energy difference.
4. This bond is usually formed between metals and non-metals.
5. This bond is very strong.
6. As a result of this bond ionic compounds are formed.
7. It is always formed between two different atoms.
8. It is formed when difference of electro-negativity of combining atoms is 1.7 or more.

Covalent Bond
1. Covalent bond is formed by the mutual sharing of electrons between two atoms.
2. Covalent bond may be formed between similar or dissimilar atoms e.g. H2, O2, HCl etc.
3. In covalent bond atoms have very small electro-negativity or ionization energy difference.
4. This bond is usually formed between non-metals only.
5. This bond is comparatively less strong.
6. As a result of this bond covalent compounds are formed.
7. It is formed between similar and different types of atoms.
8. It is formed when difference of electro-negativity of combining atoms is less than 1.7.

Ionic and Covalent Compounds
Ionic Compounds
1. The ionic compounds are usually solid, hard and brittle.
2. The ionic compounds are good conductors of electricity either in fused state or in the form of aqueous     solution.
3. Ionic Compounds have high melting points and boiling points.
4. Ionic compounds have high melting points and boiling points.
5. Covalent compounds are mostly volatile.

Covalent Compounds
1. Covalent compounds exist in all the three states i.e. gas, liquid and solid.
2. A pure covalent compound does not conduct electricity.
3. These have usually low melting and boiling points.
4. These are soluble in water.
5. These are insoluble in water but soluble in organic solvents.

Co-Ordinate Covalent and Covalent Bond
Co-Ordinate Covalent Bond
1. It is a bond in which the shared electron pair is denoted by one atom only.
2. One atom donates electrons but other has no contribution.
3. Lewis acids and bases always from this bond.
4. It is represented by ->.
5. It is formed by the donation of an electron apir by one of the two bonded atoms.
6. It is formed by the completely filled atomic orbital.

Covalent Bond
1. It is a bond formed by the mutual sharing of electrons.
2. In the shared electron pair both atoms have equal contribution.
3. Lewis acids and bases do not form this bond.
4. It is represented by _.
5. It is formed by the mutual sharing of electrons between atoms.
6. It is formed by the overlap of partially filled atomic orbital.

Polar and Non-Polar Covalent Bond
Polar Covalent Bond
1. The covalent bond between two atoms having different electro-negativity is called a polar covalent     bond.
2. In a polar bond, the shared electron pair is not equally attracted by the bonded atoms.
3. Bonded atoms become slightly charged and acquire partial =ve and -ve charges.
4. It has an ionic character.
5. The bond energy is greater.

Non-Polar Covalent Bond
1. The covalent bond between two atoms having same electro-negativity is called a non-polar covalent     bond.
2. In a non polar bond, the shared electron pair is equally attracted by the bonded atoms.
3. Bonded atoms remain electrically neutral and do not acquire partial charges.
4. It has no ionic character.5. The bond energy is lesser.

Electrolytic and Galvanic or Voltaic Cell
Electrolytic Cell
1. It is a device for converting electrical energy into chemical energy. It means by passing current through     an electrolyte, chemical reaction takes place.
2. It consists of a vessel containing an electrodes and a source of direct current (battery).
3. Example: Electrolysis of aqueous solution of NaCl.

Galvanic or Voltaic Cell
1. It is a device for converting chemical energy into electrical energy. It means spontaneous redox reaction     is used for the production of electric current. This cell was prepared by L.Galvani and A.Volts, hence     named as Galvanic or Voltaic Cell.
2. It consists of two half-cells. Each half cell consists of an electrodes and the solution with which it is in     contact.
3. Example: Daniel Cell-Zn/ZnSO4 and Cu/CuSO4 cell.

Solution and Suspension
Solution
1. The size of particles is between 0.1 to 1nm.
2. Particles cannot be seen with low power microscope.
3. It is homogeneous.
4. Particles do not settle down.
5. It is transparent.
6. Components cannot be separated by filtration.

Suspension
1. The size of particles is larger than 1000nm.
2. Particles can be seen by low power microscope.
3. It is heterogeneous.
4. Particles settle down.
5. It is not transparent.
6. Components can be separated by filtration.