Chemistry Quiz 2

Electroplating is the process of coating a metal with a thin layer of another metal by electrolysis to improve the metal's corrosion resistance. The metals commonly used for electroplating are nickel, chromium, cadmium, copper, gold, palladium, platinum, ruthenium, silver, tin and zinc.

A limnic eruption (lake overturn) is a natural disaster in which dissolved carbon dioxide suddenly erupts from deep lake waters, forming a gas cloud capable of suffocating wildlife, livestock, and humans.

Ultraviolet radiation striking the earth is due to the depletion of ozone. The ozone layer in the stratosphere absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface. Most importantly, it absorbs the portion of UV light called UVB.

The lustre of the metals is because of the reflection of light due to the presence of free electrons. The free electrons can move freely in the metal causing any light incident on them to get reflected back.

Carbon dioxide is a major greenhouse gas. Earth's greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic).

Cobalt oxide (Co₃O₄) imparts a deep blue colour to the glass. Before the glass can cool and solidify, cobalt can be added to the mixture to give the glass a deep blue colour.

Candle is a mixture of Paraffin wax and stearic acid. Paraffin wax (C_nH_2n+2) is a white or colourless soft, solid wax. It's made from saturated hydrocarbons. Stearic acid, another name for octadecanoic acid CH₃(CH₂)₁₆COOH, is one of the most common fatty acids.

Milk of magnesia is also known as magnesium hydroxide. It is an inorganic compound with the chemical formula Mg(OH)₂. It occurs in nature as the mineral brucite.

Caesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal. Caesium ionizes easily when heated or exposed to light because it is strongly photoelectric (easily loses electrons when struck by light). Cesium 133 is the element most commonly chosen for atomic clocks.

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.