Test: Metallurgy - Class 10 MCQ

A flux is added to the charge in a furnace to help remove gangue (impurities) during the extraction of metals. It reacts with impurities to form a slag that can be easily removed.

Metals are generally known for their shiny appearance (luster). A dull appearance is not characteristic of metals, which tend to be malleable, strong, and good conductors of electricity.

Aluminium is widely used in construction alloys due to its lightweight, strength, and resistance to corrosion, making it a preferred material in the construction industry.

Fermentation is a biological process used in food and beverage production and is not a method for extracting metals. The other options are all established metallurgical processes.

Froth flotation is a process specifically used to separate sulphide ores from gangue. It involves adding chemicals to create a froth that allows the desired ore to be skimmed off while impurities sink.

The activity series of metals ranks metals by their reactivity, allowing predictions about their ability to displace other metals from solutions and their general behavior in reactions.

Zinc is primarily used for galvanization, as it provides a protective coating to iron and prevents it from rusting by corroding preferentially.

Alkali metals are known for their high reactivity and low density, which typically leads to lower melting points. Hence, they do not possess high melting points compared to other metals.

Minerals are naturally occurring compounds that contain metals, generally mixed with other materials like soil and rock. They are different from ores which are specifically mined for metal extraction.

Rusting occurs due to the slow oxidation of iron when exposed to moisture and atmospheric oxygen. This process forms hydrated iron(III) oxide, commonly known as rust.

Distillation is the method used for refining volatile metals. It separates the metal from its impurities based on differences in boiling points.

The primary purpose of refining impure metals is to enhance their purity and electrical conductivity, ensuring that the metals meet specific standards for industrial applications.

During the electrolysis of alumina, oxygen gas is produced at the anode as the oxide ions lose electrons in the oxidation process.

Alkaline earth metals generally have higher densities compared to alkali metals. They are reactive but less so than alkali metals and are solid at room temperature.

Smelting is the process used to extract metals from their ores by heating and melting the ore, effectively reducing it and allowing for the removal of impurities or gangue.

The Bayer process is used to concentrate bauxite ore by converting it into sodium aluminate, which is then further processed to extract pure aluminium.

Zinc alloys are commonly used for coating iron and steel sheets to prevent rusting, a process known as galvanization. This helps extend the lifespan of these materials in various applications.

Aluminium does not react directly with water at room temperature to form aluminium oxide; instead, it typically reacts with steam to produce aluminium oxide and hydrogen.

Gangue refers to the earthy impurities, such as silica and mud, that are found mixed with ores. It is the waste material that must be separated during the extraction process.

Galvanization involves coating iron with a more electropositive metal, such as zinc, to prevent rusting. This method provides sacrificial protection, where the zinc corrodes instead of the iron.