Chemistry Quiz 4

A balloon filled with helium rises in the air because helium is less dense (lighter) than air. Helium floats because its molecules are lighter than the nitrogen and oxygen molecules of our atmosphere and so they rise above it.

The metal, which is a constituent of vitamin B₁₂ is Cobalt. Cyanocobalamin (commonly known as Vitamin B₁₂) is a highly complex, essential vitamin, owing its name to the fact that it contains the mineral, cobalt.

Electric bulbs are filled with Argon. The heat from the tungsten filament generates light and the argon helps prevent the filament from decaying.

High octane fuel contains high content of lead. If tetraethyl lead, Pb(CH₂CH₃)₄, was put into petrol, particles of lead and lead oxide PbO are formed on combustion. This helps the petrol to burn more slowly and smoothly, preventing knocking and giving higher Octane ratings.

Quartz is made of Sodium Silicate. It is a chemical compound consisting of one part silicon and two parts oxygen. It is silicon dioxide (SiO₂). Sodium silicate is made by fusing silicon dioxide (from Sand) and Sodium oxide (from Soda ash).

The process involved in making soap is saponification. Saponification is a process that involves the conversion of fat, oil, or lipid, into soap and alcohol by the action of aqueous alkali. Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. A typical soap is sodium oleate.

The colour of the most popular emerald is pure deep green. Emerald is a gemstone and a variety of the mineral beryl (Be₃Al₂(SiO₃)₆) coloured green by trace amounts of chromium or sometimes vanadium.

Peat contains recognisable traces of the original plant material. Peat is a soft, organic material consisting of partly decayed plant and mineral matter. When peat is placed under high pressure and heat, it undergoes physical and chemical changes (coalification) to become coal.

The ratio of pure gold in 18-carat gold is 75 percent. 'Caratage' is the measurement of purity of gold alloyed with other metals. 24 carat is pure gold with no other metals. Lower caratages contain less gold; 18-carat gold contains 75 percent gold and 25 percent other metals, often copper or silver.

Fructose is the sweetest sugar. Sucrose is second sweetest followed by glucose and lactose.