Carbon and its CompoundsIntroduction
Think back to this morning. Riya did: she brushed with a plastic toothbrush, drank chai from a clay kulhad, ate two rotis, packed her notebook into a cloth bag and caught a bus that runs on CNG. In the last chapter you met metals, non-metals and the compounds they form. This chapter is about one non-metal that hides inside almost everything on Riya's list: carbon.
Activity 4.1. Riya's list is mixed up below. Drag each item into the bucket for the material it is mostly made of.
Look at the last bucket. Cloth, paper, food, plastic, rubber, fuel: your teacher will tell you that almost all of them are made of compounds of carbon. How could you test that? Burn a little of each. Anything that contains carbon gives carbon dioxide when it burns, and carbon dioxide turns
So Little Carbon, So Much Stuff
Food, clothes, medicines, books, fuels, and every living thing including you: all of them are built on carbon. You might expect such an important element to be everywhere. It is not. The earth's crust holds only 0.02% carbon, in minerals such as carbonates, hydrogencarbonates, coal and petroleum, and the air holds only 0.03% carbon dioxide.
So in every 10 000 kg of the earth's crust there are only about
A tiny amount, with an enormous importance. In this chapter you will find out what makes carbon so special: the way it bonds, the chains it builds, the families of compounds those chains make, and the chemistry of three carbon compounds you meet every day — ethanol, ethanoic acid and soap.