Formula's of Molarity, Molality, Equivalent mass, no of gram equivalence and normality.

Formula's of Molarity, Molality, Equivalent mass, no of gram equivalence and normality.

Chemistry practical readings for first year students.

Chemistry practical readings: determination of heat of solution.

Chemistry practical readings and chromatograph: separate a mixture of various inks by paper chromatography.

Chemistry practical readings: determination of heat of solution.

Chemistry practical graph readings: determination of heat of solution.

Chemistry practical readings: Standardization of sodium hydroxide solution by standard solution of oxalic acid.

Chemistry practical readings: Standardization of H2SO4 solution by standard solution of NaOH.

Chemistry practical readings: Determine the amount of acetic acid in the given vinegar.

Chemistry practical readings: Determine the amount of Na2CO3 in a mixture solution.

Chemistry practical readings: Determine the amount of Na2CO3 in a mixture solution.

Chemistry practical readings: Standardization of HCl solution using a standard solution of Na2CO3.

Chemistry practical readings: Standardization of HCl solution using a standard solution of Na2CO3.

Chemistry practical readings: The given solution contains 7.0 grams of washing soda per liter. Calculate percentage purity.

Chemistry practical readings: The given solution contains 7.0 grams of washing soda per liter. Calculate percentage purity.

Chemistry practical readings: determination of NaHCO3 in a  mixture of solution.

Chemistry practical readings: determination of NaHCO3 in a  mixture of solution.

Chemistry practical readings: determination of NaHCO3 in the baking soda.

Chemistry practical readings: determination of NaHCO3 in the baking soda.

Chemistry practical readings: Find the number of molecules of water of crystallization in the given salt of Mohr's salt.

Chemistry practical readings: Find the number of molecules of water of crystallization in the given salt of Mohr's salt.

Chemistry practical readings: Find the number of molecules of water of crystallization in the given sample of  FeSO4.n H2O.

Chemistry practical readings: Find the number of molecules of water of crystallization in the given sample of  FeSO4.n H2O.

Chemistry practical readings: Standardization of potassium permanganate solution by the standard oxalic solution.

Chemistry practical readings: Standardization of potassium permanganate solution by the standard oxalic solution.

Chemistry practical readings: Titration of iodine solution against Na2S2O3 solution using starch solution as indicators.

Chemistry practical readings: Titration of iodine solution against Na2S2O3 solution using starch solution as indicators.

Chemistry practical readings: Find the strength of oxalic acid solution, using 0.02 molar KMnO4 solution.

Chemistry practical readings: Find the strength of oxalic acid solution, using 0.02 molar KMnO4 solution.

Chemistry practical readings: Determine the number of molecules of water of crystallization of oxalic acid by permanganate titration, 6.3 grams of oxalic acid have been dissolved per liter.

Chemistry practical readings: Determine the number of molecules of water of crystallization of oxalic acid by permanganate titration, 6.3 grams of oxalic acid have been dissolved per liter.

How to draw neat and tidy diagrams?

Whether in your practical copies or your Exams, the drawings and diagrams have to be labelled and neat. If you add some shadings and sketchy marks to them, the merrier.
Here are some tips and tricks to make your work look neater:

1. Never ever draw the diagrams in the middle of the page, draw them towards the left, so that there is space for labeling's.
2. The diagram should not be very close to the top or bottom, but rather in the middle. There should however be space for the main heading, which should be below the drawing, not above it.
3. Give the main heading double underlines, and the labeling's single underlines, in case you have shortage of time or space (sometimes the labeling's are too many). 
4. Make the line end of the labeling's prominent by darkening the ends of the line.
5. Always use a full stop after each labeling.
6. make the first drawing with a light pencil, so that it can be rubbed off, when wrong. Once the first correct sketch has been drawn, only then use a dark pencil.
7. Use a tissue paper or cotton bud to shade or blend the shade.
8. Make sure your hands are clean before starting the labeling. Often shading leaves the hands gray because of the lead, so clean them up before starting the labeling.

Molecular Orbital Theory ... Lecture by "freelanceteach".

Is any compound 100% ionic?

There is no compound which is 100% ionic. CsF should be most ionic but Francium is radio active.

CsF is not very ionic.

Important Applications of Batteries and Fuel Cells.

Application of batteries and fuel cells.

High specific power is required for the large mechanical load. Low operating temperatures can arise. safety and environmental concerns are also an issue.

• Pb/Acid Cell:

It is certainly and exclusively used in theses applications:
1. ELECTRICALLY POWERED VEHICLES (ECV's)
They used batteries to replace the combustion engines. The current technology: Ni/base cells or Pb/acid cells will not suffice  to provide a car with the same operating parameters as the combustion engine.
2. HIGH POWER APPLICATIONS.
They are used for portable high power applications.
*portable computers: a rpidly growing market, currently using:
Ni/Cd cells.
NiMH cell.
Lithium ion cell.
*Power tools.
*Flashlights.
*Medical devices.

• Primary Cells:

They are used in:
1. PORTABLE LOW POWER APPLICATIONS:
*watches.
*meters.
*cameras.
*calculators etc.
In these devices low power densities are often acceptable but low self discharge rates and high energy densities are desirable to provide long service life.
Lithium batteries are more often used.
2. MILITARY APPLICATIONS:
*power for missile guidance.
*communication devices.
*drive or activation.
3. HEARING AIDS:
*mercury battery.
*silver oxide battery.
*zinc/air battery.
High volumetric energy density allow for smaller batteries.

• Fuel Cells:

They are used in:
1.FUEL CELL POWER.
*vending machines.
*vacuum cleaners.
*high way road signs.
2.POWERING.
*buses.
*boats.
*trains.
*planes.
*scooters.
*bicycles.
3.MINIATURE FUEL CELLS.
*cellular phones.
*laptop computers.
*portable electronics.
4.POWER TO FACILITIES.
*hospitals.
*credit card centers.
*police stations.
*banks.
5.ELECTRICITY PRODUCTION.
*waste water treatment plants.
*land fills.
They convert methane gas to produce electricity.
6.MICRO FUEL CELLS.
*pagers.
*video recorders.
*portable power tools.
*smoke detectors.
*low power remote devices.
*burglar alarms.
*hotel locks.
*meter readers.

Ionic Compound, Covalent Compound and Coordinate Covalent Compounds.

Ionic Compound, Covalent compound and coordinate covalent bond.

Understanding The Quantum Numbers.

Principle quantum numbers, Azimuthal quantum number,
 magnetic quantum number and  spin quantum number.

What are Inter-molecular forces?

What are the intermolecular forces? Explain in detail.

DEFINITION:

“The force of attraction present in the molecule of a compound is called intermolecular forces.”

CHARACTERISTICS OF INTERMOLECULAR FORCES:

1.       WEAK FORCES:

Usually these forces are very weaker than the bonding forces present with in these molecules.

2.       IN LIQUIDS AND GASES:

These forces are very weak among the molecules of gases and liquids.

3.       MELTING AND BOILING POINTS:

The melting and boiling points of liquids and solids depend upon the strength of these forces.

TYPES OF INTER MOLECULAR FORCES:

They are of three types:

·         Vander waal’s forces or London Dispersion Forces.

·         Dipole dipole forces.

·         Hydrogen Bonding

Importance of Chemistry and the harmful aspects of Chemistry.

Question.a. Explain the role of importance of chemistry.

b. How chemistry proves to be dangerous for us?

IMPORTANCE OF CHEMISTRY:

Chemistry plays an important role in our daily lives. It has not only changed our standard health conditions but infact almost every field of our lives.

1.       MAJOR GIGTS:

Synthetic fibers, nylon, plastics, medicines, soaps and detergents, cement, glass and fertilizers, cosmetics and explosives are the major gifts of chemistry.

2.       WELL BEING OF MANKIND:

Chemistry has contributed a lot to the well being of mankind in the form of food, clothing, shelter and medical treatment.

3.       AGRICULTURE:

Crops are being protected by using fertilizers, insecticides and pesticides.

4.       ARTIFICIAL PRODUCTS:

The production of a variety of artificial products has brought a revolution in our clothing. We wear colorful and fine dresses for all seasons.

5.       CONSTRUCTION OF BUILDINGS:

Cement, cast iron, pig iron, bricks, glass etc. are used in construction and a result from the knowledge of chemistry.

6.       PAINTS:

The attractive and colorful paints used for making our houses vibrant.

7.       Petroleum and petrochemicals provide countless facilities to us.

8.       Polyester fiber, fiber glass, multi color glasses, crockery, steel and alloys are the product of chemistry.

9.       NUCLEAR CHEMISTRY:

It provides us radio isotopes for the treatment of many diseases such as cancer. It also gives us atomic energy which can be used in various fields.

10.   ENVIRONMENTAL CHEMISTRY:

It gives us the knowledge about how to protect our environment from pollution.

DANGEROUS ASPECTS OF CHEMISTRY:

Although Chemistry has made our lives highly comfortable but it can be dangerous for us because:

11.   The smoke from Chemical industry and increasing number of automobiles cause air pollution which is responsible for damaging our environment. The polluted air has a very harmful effect on our health.

12.   The waste coming from chemical industries is full of dangerous chemicals and metals. It damages our lands, canals, rivers and most importantly our aquatic life.

13.   Excessive chemical sprays on our crops are affecting our daily lives.

14.   Chemical weapons and atom bombs have killed millions of people.

Chapter 4: Liquids and Solids: ammonia and refrigerants.

Question 1
a) Ammonia is a colorless gas with a very pungent smell. It turns damp red litmus blue which indicates it's basic nature. It is lighter than air. It is easily liquefied by cooling or by compressing, as it is easy to transport in tanks and cylinders. It has a high critical temperature. Because Ammonia can be liquefied easily and it has a high heat of vaporization, one of its uses is as refrigerant.
Refrigerants are the materials used for cooling. the method of refrigeration is achieved by lowering the temperature of ammonia below that of its surroundings. The usual method is by vapor compression. Many condensable vapors are used as refrigerants e.g. chlorofluorocarbons (freons), ammonia and carbon-di-oxide but ammonia is the only one which does not cause depletion of ozone.

Facts about Ammonia:
Boiling point: -33.5 degree centigrade.
Melting point: -77.7 degree centigrade.

Roults Law ...

by F. M.Roult (1887)
The relative lowering of vapor pressure of a solvent which is caused by the addition of a non-volatile solute is equal to the mole fraction of the solute in the solution.
This causes elevation of boiling point, depression of freezing point.
This law is strictly applicable to ideal solutions because it assumes that there is no chemical interaction between the solute and the solvent molecules.


Ideal Solution:

1. A solution in which thermodynamic activity of each component is proportional to its mole fraction (Roults law)
2. Zero heat of mixing.
3. Zero volume change.
4. Ideal entropy of mixing.

Note: Only isotropic elements form ideal solutions although many mixtures shoe behavior close to ideality