CHEM 181 Study Guide - Midterm Guide: Fritz Haber, Ammonium Nitrate, Hydroponics

• School: McGill University
• Department: Chemistry
• Course: CHEM 181
• Professor: Joe Schwarcz

Document Summary

Today: only 2% of the population supplies food for the world in contrast to 70% We are already having difficulty feeding the population we have today thus it"s best to use pesticides to be able to keep foods. Can use manure, but not enough shit to sustain the world. Justus von liebig: what is in manure that allows for crops to grow: 4 major nutrients needed, nitrogen, phosphorus, potassium, various other elements in small amounts. In stores, fertilizers are sold in different ratios of these 4 depending on which plants because they all require different combinations. *fritz haber: combined nitrogen and hydrogen to make ammonia (2nh3) Most widely used fertilizer bc good source of nitrogen. Can also be used as an explosive. Disadvantage: slowly decomposes to form nitrous oxide / laughing gas greenhouse gas. Ground up coconut shells are used, etc. don"t need soil: but need a good ratio of the nutrients.