Question

In order to refine 'blister copper ' it is melted in furnace and is stirred with green logs of wood The purpose is: (1) to expel the dissolved gases in blister copper. (2) to reduce the metallic oxide impurities with hydrocarbon gases liberated from the wood. (3) to bring the impurities to surface and oxidize them. (4) to increase the carbon content in the copper.

Short answer

Option 2: To reduce the metallic oxide impurities with hydrocarbon gases liberated from the wood.

Step-by-step solution

Read the question carefully

Understand the process described: Blister copper is melted in a furnace and stirred with green logs of wood.

Identify the purpose as per each option

Consider each option one by one to determine its correctness in the context of refining blister copper. Pay attention to the processes and reactions taking place.

Evaluate Option 1

Option 1 states that stirring with wood expels dissolved gases. Stirring can help release trapped gases but it is not the primary purpose.

Evaluate Option 2

Option 2 mentions reducing metallic oxide impurities with hydrocarbon gases from the wood. The hydrocarbons can reduce metallic oxides, making this option correct.

Evaluate Option 3

Option 3 suggests bringing impurities to the surface and oxidizing them. Wood stirring does not typically lead to oxidation; it uses hydrocarbons for reduction.

Evaluate Option 4

Option 4 proposes increasing carbon content in copper. Copper refining aims to reduce impurities, not increase carbon, eliminating this option.

Select the correct answer

Based on evaluation, Option 2 is the accurate purpose of refining blister copper using green logs of wood.

Key concepts

metal purification

Refining metals involves removing impurities to produce high-quality, pure metals. In the context of blister copper, the goal is to purify the copper by removing unwanted elements. When blister copper is melted in a furnace and stirred with green logs of wood, several purification processes occur.

Blister copper primarily contains copper along with impurities like sulfur, iron, and oxygen. To achieve purification:

• Dissolved gases like oxygen need to be expelled because they weaken the metal's structure.
• Impurities must be converted to a form that can be easily removed.

The use of green logs of wood during the refining process helps with these steps as the hydrocarbons in the wood interact with the impurities.

hydrocarbon reduction

Hydrocarbons, found in green logs of wood, play a crucial role in the refining process of blister copper. When the wood is heated in the furnace, it releases hydrocarbon gases. These gases are essential for a chemical reaction known as hydrocarbon reduction.

This type of reduction works by reducing metallic oxide impurities present in blister copper. Here's how it works:

• The hydrocarbon gases react with metallic oxides, such as copper oxide (CuO).
• This reaction converts copper oxide back into pure copper (Cu) and carbon dioxide (CO₂).

Through hydrocarbon reduction, impurities are removed, and pure copper is obtained. This makes the metal stronger and more conductive.

metallic oxide impurities

Metallic oxide impurities are unwanted substances that can weaken the quality of metal. In the case of blister copper, these impurities include oxides such as copper oxide and iron oxide.

When these oxides are present, they need to be reduced or removed to improve the metal's properties. The refining process involving green logs of wood addresses this by:

• Using the hydrocarbon gases from the wood to reduce oxides into their metallic form.
• Helping bring impurities to the surface of the molten copper where they can be separated.

By focusing on the reduction of metallic oxide impurities, the refining process ensures the production of high-quality copper suitable for various applications such as wiring and electronics.