Chemistry Chapter 15 | 2nd Year

 Chapter 15 Notes | Chemistry 2nd Year

“Common Chemicals Industries In Pakistan”

1. Agriculture has been one of the oldest indsutry known to man. Since 5000 B.C Chinese have been using animals manure in their fields.
2. Fertilizer is the natural or artificial substance containing the chemical elements that improve growth and productiveness of plants.
3. Natural fertilizers are materials derived from plants and animals whereas artificial fertizers consist of manufactured material like urea, super phophate and ammonium nitrate, etc
4. Syntehtic fertilizers are maily used fot making up the immediate deficiency of essential nutrient elements needed in relatively large amount.
5. The nutrients required in a very small amount for growth of plants are called micro-nutrients and the nutriets which are required in a very large amount are called macto nutrients.
6. Urea and ammonium nitrate are the majot nitrogeneoue fertilizers whereas super phosphat and triple phosphate are important phosphatic fertilizers/
7. Cement is a very impotant building material which was first introduces in 1824 by an English mason joseph Aspdin.
8. Cement is the material obtained by burning an intimate mixture of cacarious and argillaceous materials at suffeciently high temrature to produce clinckers wihich are subsequently griound to a fine powder. Wet process is generally used inproduction of cement.

See Also: Chemistry 2nd Year Paper Scheme 2021