Chemistry Quiz 4

Oxygen is the most abundant element in the human body accounting for approximately 65% of a person's mass. Each water molecule consists of two hydrogen atoms bonded to one oxygen atom, but the mass of each oxygen atom is much higher than the combined mass of the hydrogen.

The gas that is used in the manufacture of vanaspati ghee is hydrogen. Hydrogenation is a process where manufacturers add hydrogen to a liquid fat, such as vegetable oil, to turn it into a solid fat at room temperature.

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.

Stainless steel is an alloy of chromium, carbon and iron. It contains 10 to 30 percent chromium, less than 1.2% carbon and other alloying elements.

The gas used in the artificial ripening of fruits is Acetylene (C₂H₂). Calcium carbide (CaC₂) is used for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is similar in its effects to the natural ripening agent, ethylene. Note: ethylene (C₂H₄) is the natural ripening agent of plants.

In a lead-acid battery, the cathode is made of lead dioxide, and the anode is made of metallic lead. The two electrodes are separated by an electrolyte of sulfuric acid.

A catalytic converter is a device used in motor vehicles to reduce the damage caused to the environment by poisonous gases. Catalytic converters are generally made from transition metals. Transition metals such as platinum (Pt), palladium (Pd), and rhodium (Rh) are used in the catalytic converters.

An amalgam is an alloy of mercury with another metal. It may be a liquid, a soft paste or a solid, depending upon the proportion of mercury.

Soap is prepared by boiling caustic soda with Fats. Soap is prepared by hydrolyzing fat under alkaline (basic) conditions. The reaction is called saponification, and produces one molecule of glycerin and three molecules of soap, for each molecule of fat taken.

Hydrogen peroxide (H₂O₂) is water (H₂O) with an extra oxygen molecule. H₂O₂ contains a single oxygen-oxygen bond. When its oxygen-oxygen bond breaks, hydrogen peroxide decomposes into water and oxygen.