Metallurgical Processes

Samples are passed through propylene oxide in the process of embedding. After treating with propylene oxide, samples are infiltrated with an epoxy resin and then embedded directly in water-miscible acrylic resin.

Annealing is the process of repeatedly heating and cooling an iron rod to increase strength.

Non-ferrous materials lack mechanical strength. Hence, the same are not used.

Corrosion is the other name of oxidation of iron.

This is the correct option as this statement is false regarding electroplating an iron object with copper metal. Copper sulphate solution, and not iron sulphate solution, is taken as an electrolyte as it contains copper metal in dissolved form as copper ions.

This is the correct option as the chemical effect of electric current is not used in the industry for the separation of certain metals from the ores. It is used for the production of certain metals from the ores.

This is the correct option. Iron cannot be used for electroplating because it corrodes and rusts.

Copper is dark brown in colour, which helps in separation by mechanical picking.

Acid rain slowly erodes the cement, limestone and marble of buildings and corrodes steel and other metals.

Option 3 is correct.

It is an important physical property of metals. For example, gold and silver are both malleable and ductile.

Alloys are used because they have high melting point which ensures that the heating element does not melt upon heating continuously. The element chosen as heating element should be such that it has high resistance because of Joule's law of heating: Heat is directly proportional to resistance, i.e. more resistance more heat.

Refining is the final process in metallurgy where impure metal (obtained from reduction of ore) is purified to remove residual impurities and obtain the pure metal. Different refining methods include liquation, distillation, poling, electrolytic refining, and zone refining. Roasting is an earlier process that converts sulfide ores to oxides, not a purification method. Regulating is unrelated to metallurgy.

Aluminium foil is used to make medicine wrappers because it is malleable.

Tin is less reactive than zinc and forms a protective oxide layer that prevents food contamination. Zinc is more electropositive in the reactivity series, so it would react more readily with acidic food contents, potentially contaminating the food and compromising the can. Tin's lower reactivity makes it ideal for food container lining.