Law of Multiple Proportions.

LAW OF MULTIPLE PROPORTIONS:

This law was proposed by John Dalton (1763-1844) in the year 1803. He was not a good experimenter (perhaps because he was colorblind), but he skillfully used the results of others in formulating this law.

STATEMENT:

“When two elements combine together to form more than one compound, the different weight of one of these elements which combines with the definite weight of the other elemts are in simple ratio.”

EXAMPLES:

Compounds of “H” and “O”

S. No	Compound	Formula	Wt of O	Wt of H	Ratio
1	Water	H2O	16	2	2:16
2	Hydrogen peroxide	H2O2	32	2	2:32

Compounds of “C” and “O”

The oxygen-to-carbon mass ratio in carbon-di-oxide is twice that found in carbon monoxide.

S. No	Compound	Formula	Wt of C	Wt of O	Ratio
1	Carbon monoxide	CO	12	16	12:16
2	Carbon-di-oxide	CO2	12	32	12:32

Compounds of “N” and “O”

S. No	Compound	Formula	Wt of N	Wt of O	Ratio
1	Nitrous oxide	N2O	28	16	28:16
2	Nitric oxide	N2O2=NO	28	32	28:32
3	Nitrogen trioxide	N2O3	28	48	28:48
4	Nitrogen tetra oxide	N2O4=NO2	28	64	28:64
5	Nitrogen pent oxide	N2O5	28	80	28:80

CONCLUSION:

It is clear from all these examples that the law of multiple proportions is verified.

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.

ESSAY WRITING QUOTES AND FACTS:

1.     Ruskin called books the “King’s treasures"
2. “God made the country and man made the town.” Cowper
3. “There is not to reason why, there is but to do and die” Alfred Lord Tennyson (“The Change of the Life Brigade” )
4. “Trials are a veritable curse” Christ
5. Lord Macaulay introduced the system of education (East India Company)
6. Einstein failed Mathematics, Newton did MA Mathematics in third grade, Hafeez Jalandhry studied till class VII, Allama Iqbal got third division in MA Philosophy and Hitler did simple matric.
7. “Woman is the root of the evils.” The Old Testament.
8.   Surah Nisah is about the rights and duties of women.
9. “Verily the paradise lies under the feet of the mother.”
10. The tidings of paradise are for those who bring up two daughters.
11. The hand that rocks the cradles rules the world.
12. In Iran 40% women work.
13. “It is essential for every Muslim man and woman to acquire knowledge.”
14.  “Hope springs eternal in the human breast, man never is but always to be blest.” Pope
15. Science is itself never good nor evil.
16. 70% diseases are due to tension.
17. Sound mind is a sound body.
18. Cleanliness is next to Godliness.
19. History repeats itself.
20. French Revolution 1789
21. “History is the biography of great men”
22. “History is a bundle of lies.”
23.   “Patriotism is the last refuge of a scoundrel”
24. “In modern wars there are no winners.”
25. All is fair in love and war.
26. NIFA= Peshawar nuclear institute.
27. 1938, Helm and Stressman (fission 1942 chain reaction)
28. International Atomic Energy Commission.
29. Sir Ganga Ram and Imran Khan’s hospitals.
30. Money makes the mare go.
31. “What is the use of the new born baby?” Professor Faraday on the nature of Chemistry.
32. No knowledge without college.
33.    “Home keeping youths ever have homely wits” Shakespeare.
34.  Co-education started in Switzerland.
35.  When you educate a man you educate an individual. When you educate a woman you educate a nation.
36.  John Milton was blind so his daughter wrote for him “Paradise lost and Paradise regained.”

Break Break Break

Break, Break, Break:

Explanation:

O sea! Go break yourself on the shores of the sea shore. Strike your waves against the gloomy and emotionless ridges of the shore. The inner deep emotions need to be brought forth. They should make their impact as the waves make their impact. Even though this might break them but it will prove them to be alive. As the waves do their work, I would try to do mine by uttering the thoughts and ideas that are building up with in me. I need to find the courage to speak them out loud. Fate seems to be dead to the human feelings and inert to their emotions.

It is okay for the fisher man’s son to shout while playing with his sister and it is also fine for the son of the sailor too sing in his boat which floats in the bay. They can all be happy and gay. They cannot sense the sadness and rising tides of emotions within me, the depressing thoughts that I have are because they are young and free from the oppressive fate, the wicked tyrannous will of life. They are still too young to imagine my grief, my horror and my inner turmoil. They still have the right to enjoy life as they can. They need not worry about their future, their paths and journeys ahead. They can take pleasure now when they have the opportunity to do so, to live life to the full and to laugh and play with no care what so ever of what lies beyond.

Law of Reciprocal Proportions: statement, example and conclusion.

Here is an example to tell how you will solve notes on the four chemical laws in Chapter 1.

Write a note on the Law of reciprocal proportions.

LAW OF RECIPROCAL PROPORTIONS:

This law was proposed by Ritcher in the year 1799. This law is also known as the “law of equivalent weights”.

STATEMENT:

“The weights of the elements which separately combine with the fixed weight of the third element are either the same or are the simple multiples of which they combine with each other.”

EXAMPLE:

Hydrogen combines with Oxygen to form water: H2O

2:16

1:8

Hydrogen combines with Carbon to form Methane: CH4

12:4

3:1

When carbon and oxygen combine with each other they for Carbon-di-oxide: CO2

12:16×2

12:32

3:8

CONCLUSION:

In both cases the mass ratio is the same 1.e 3:8. It proves the law of reciprocal proportion.