1)   2a) C16H21N3 2b) The first similarity is the two carbon chain with a nitrogen at the end (-C-C-N-). The second similarity is the -N-C-N- chain. The spatial arrangements of the flat 5-ring in histamine is also similar to the flat 6-ring in antihistamine. With these similarities, antihistamine can then bind to histamine receptor sites on cells more tightly than histamine itself.… Read more →

1. Styrofoam is able to dissolve in acetone because acetone is a good solvent for polystyrene, which is what styrofoam is made of. After the acetone has evaporated, what’s left is a very solid and dense styrofoam. This is because styrofoam is made with foaming agents, which means that it contains lots of air pockets. These air pockets then get… Read more →

1a. Coal-fired plants produce massive amounts of sulphur dioxide. These compunds then react with other compunds in the air to form fine particles that reduce the overall visibility. Sulphuric acid from coal burning form tiny droplets by reacting with the water vapour, which does not absorb sunlight, causing even poorer visibility. 1b. Naturally, rain is slightly acidic, with a pH… Read more →

a. Add treatment solutions b. Boiling c. Water filters -Adding chemicals like chlorine dioxide or iodine will kill bacteria and viruses leaving behind chemicals and sediments. They can be bought at relatively cheap prices. -Boiling wipes out bacteria and viruses very effectively but does not get rid of sediments like mud and sand or chemicals. It is very cheap to… Read more →

Greenhouse gases absorb the energy emitted by the Earth’s surface, thus resulting in enhanced greenhouse effect. Since the net energy leaving the Earth’s surface is lesser than the solar energy striking Earth’s surface, therefore the earth is not cooling rapidly. The picture depicts snowing, which is the opposite of what the two men thought of global warming because the word… Read more →

a) Exothermic reaction as it is a combustion reaction and it releases heat energy. b) Endothermic reaction. The body loses heat which is gained by the water, thus allowing it to change from liquid to gaseous state. c) Endothermic reaction. The ice absorbs heat energy from the surroundings. 2. In an exothermic reaction, a large negative net energy change, bonds… Read more →