Chapter 15 Notes | Chemistry 2nd Year
“Common Chemicals Industries In Pakistan”
- Agriculture has been one of the oldest indsutry known to man. Since 5000 B.C Chinese have been using animals manure in their fields.
- Fertilizer is the natural or artificial substance containing the chemical elements that improve growth and productiveness of plants.
- Natural fertilizers are materials derived from plants and animals whereas artificial fertizers consist of manufactured material like urea, super phophate and ammonium nitrate, etc
- Syntehtic fertilizers are maily used fot making up the immediate deficiency of essential nutrient elements needed in relatively large amount.
- 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.
- Urea and ammonium nitrate are the majot nitrogeneoue fertilizers whereas super phosphat and triple phosphate are important phosphatic fertilizers/
- Cement is a very impotant building material which was first introduces in 1824 by an English mason joseph Aspdin.
- 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