Question

Look around your room right and now and select five objects. Propose a classification scheme for these objects and discuss the chemical composition of each object.

Answer 1

five objects:

1) desk; 2) chair; 3) bed; 4) shoes; 5) closet

classification scheme:

use classification:

• to write: desk,
• to sit: chair
• to rest: bed
• to protect feet: shoes
• for storage: closet

material classification:

• wood: desk, chair, closet, bed
• rubber: shoes

chemical composition for wood (desk, chair, closet and bed): is essentially a set of elongated, parallel cellulose fibers bonded by a material known as lignin containing hemicellulose also a kind of filler. In composition are most hydrogen, oxygen, carbon and nitrogen with lesser amounts of potassium, sodium, calcium, silicon and other elements.

chemical composition for rubber (shoes): natural rubber shoes, in their natural state is a white or colorless hydrocarbon. The simplest compound rubber is isoprene or 2-methylbutadiene, whose chemical formula is C5H8. At the temperature of liquid air, around -195 ° C, the pure rubber is a hard, transparent solid. From 0 to 10 ° C it is brittle and opaque, and above 20 ° C becomes soft, flexible and translucent. By mechanically kneading or when heated above 50 ° C, the rubber becomes sticky plastic texture. At temperatures of 200 ºC or above it decomposes.