Question

Which of the following statement is true for interstitial carbides? (1) They are mostly formed by the transition clements particularly the \(\mathrm{Cr}, \mathrm{Mn}\) and Fe groups. (2) They have typically very high melting point and very hard. (3) Tungsten carbide is used for cutting tools. (4) \(\Lambda\) ll arc correct.

Short answer

All are correct.

Step-by-step solution

Identify the Answer Choices

Look at each of the provided statements to understand what they are asserting about interstitial carbides.

Examine Statement 1

Evaluate whether interstitial carbides are mostly formed by the transition elements, particularly Cr, Mn, and Fe groups. Interstitial carbides typically involve transition metals where smaller nonmetal atoms fit within the interstices (spaces) of the metallic crystal lattice. Thus, this statement is generally true.

Examine Statement 2

Check if interstitial carbides have very high melting points and are very hard. Interstitial carbides are known for their extreme hardness and high melting points due to the strong bonding between the metal and carbon atoms. Therefore, this statement is also true.

Examine Statement 3

Determine the use of tungsten carbide in cutting tools. Tungsten carbide is widely used in the manufacturing of cutting tools due to its extreme hardness and ability to retain a sharp edge. This confirms that statement 3 is true as well.

Select the Correct Answer

Since statements 1, 2, and 3 are all true, the correct answer is: 'All are correct.'

Key concepts

transition elements

Transition elements are a group of metals found in the central block of the periodic table. These elements are known for their ability to form various alloys and compounds. Some key features of transition elements include:

• They have multiple oxidation states, which means they can lose different numbers of electrons.
• They often form colored compounds, which make them useful in dyes and pigments.
• They exhibit paramagnetic properties, meaning they are attracted to magnetic fields.

These properties arise because transition elements have partially filled d-orbitals. This electron configuration allows for a variety of chemical bonds and coordination complexes. For example, elements like chromium (Cr), manganese (Mn), and iron (Fe) are transition metals that commonly form interstitial carbides. In these structures, small carbon atoms fit into the spaces within the metal lattice, resulting in extremely hard and strong materials.

high melting point

Materials with high melting points are typically capable of withstanding extreme temperatures without losing their structural integrity. Interstitial carbides, such as tungsten carbide (WC), are famous for their incredibly high melting points. Some factors that contribute to the high melting points include:

• Strong metallic bonds formed between the transition metal atoms.
• The presence of carbon atoms which strengthen the lattice structure.
• High density and compactness of the metal-carbon framework.

High melting points are beneficial in various industrial applications, especially where exposure to high heat is common. The extreme hardness and heat tolerance of interstitial carbides make them ideal candidates for environments that demand durability and longevity.

cutting tools

Cutting tools are essential in manufacturing and machining processes. They need to be extremely hard and able to retain a sharp edge under stress. Tungsten carbide is a perfect material for these tools because it is exceptionally hard and maintains its sharpness. Key benefits of using tungsten carbide in cutting tools include:

• Increased cutting speed due to its hardness.
• Longer lifespan of the tool, reducing the need for frequent replacements.
• Ability to cut through tough and abrasive materials with ease.

The use of tungsten carbide in cutting tools has revolutionized industries such as metalworking, mining, and construction. Its ability to retain a sharp edge at high temperatures makes it invaluable for processes that involve significant heat generation, such as drilling, milling, and turning.