Practice MCQ Questions and answers on Chemistry-GK

Aluminum powder is a highly flammable powder created by grinding aluminum into fine grains of material. In times past, this flammable metal powder was used in photography to create bright flashes during a photographic session. Today, aluminum powder is one of the tools utilized in various applications of pyrotechnics, including the creation of fireworks displays. Used primarily as an inlay compound, the aluminum powder can easily be used to set cut pieces of wood into position and also fill in any tiny gaps that may be present at the joints. Since only a minute amount of powder is necessary for functions of this type, the chances of ignition are somewhat limited.

Of the following commonly used materials, the one that is not an alloy is copper.

The manufacture of iron ore involves the process of reduction. Important ores of iron: Haematite, Magnetite.

Bauxite is best defined as an aluminum ore of varying degrees of purity in which aluminum in the form of aluminum hydroxide or aluminum oxide is the largest single constituent.

Tungsten is not present in stainless steel.

Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.

Bauxite is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite ,boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO₂. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821. Lateritic bauxites (silicate bauxites) are distinguished from karst bauxite ores (carbonate bauxites). The early discovered carbonate bauxites occur predominantly in Europe and Jamaica above carbonate rocks (limestone and dolomite), where they were formed by lateritic weathering and residual accumulation of intercalated clays or by clay dissolution residues of the limestone.

The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS₂. Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid.

Haematite : Copper is not correctly matched.