Interstitial Compounds and Alloy Formation - UNSOLVED PRACTICE SET
Chapter: d and f Block Elements | Topic: Interstitial Compounds and Alloy Formation
INTERSTITIAL COMPOUNDS AND ALLOY FORMATION - UNSOLVED PRACTICE SET
Topic: Interstitial Compounds and Alloy Formation
Multiple Choice Questions
Q1. Interstitial compounds are formed when small atoms like H, B, C, or N are trapped in:
- The interstitial sites of metal lattices
- The valence shell of metal atoms
- The nucleus of metal atoms
- The empty d-orbitals of transition metals
Q2. Which of the following is NOT an interstitial compound?
- TiC
- Fe₃C
- VC
- NaCl
Q3. Steel is an alloy of:
- Iron and carbon
- Iron and chromium
- Iron and nickel
- Iron and manganese
Q4. Interstitial compounds are generally:
- Soft and non-conducting
- Very hard and retains metallic conductivity
- Gaseous at room temperature
- Soluble in water
Q5. Brass is an alloy of:
- Cu and Zn
- Cu and Sn
- Cu and Ni
- Cu and Ag
Q6. The formation of interstitial compounds is a characteristic property of:
- s-block elements
- p-block elements
- d-block elements
- Noble gases
Short Answer Questions
Q7. What are interstitial compounds? Name two properties that make them different from their parent metals.
Q8. Why do transition metals form interstitial compounds easily? What is the role of their atomic size in this process?
Q9. Distinguish between an alloy and an interstitial compound. Give one example of each.
Q10. Why is steel harder than pure iron? Explain in terms of the structure of steel.
Q11. Bronze is an alloy of copper and tin. Why was bronze historically important for making tools and weapons?
Q12. What is stainless steel? Name the elements present in it and explain why it resists corrosion.
Long Answer Questions
Q13. (a) What are interstitial compounds? How are they formed?
(b) Describe the characteristic properties of interstitial compounds.
(c) Why do transition metals readily form interstitial compounds?
(d) Give three examples of interstitial compounds and mention their uses.
Q14. (a) What are alloys? How are they classified?
(b) Explain the following alloys with their composition and uses:
(i) Brass
(ii) Bronze
(iii) Stainless steel
(iv) Duralumin
(c) Why are alloys generally harder and more corrosion-resistant than pure metals?
Q15. (a) Explain why transition metals readily form alloys with each other.
(b) A metallurgist wants to create a lightweight, strong alloy for aircraft construction. Which metals would you suggest and why?
(c) Explain the structure of steel at the atomic level. How does the carbon content affect the properties of different types of steel (mild steel, medium steel, high carbon steel)?
Numerical / Application-Based Problems
Q16. The following table gives information about some alloys:
| Alloy | Composition | Properties | Uses |
|---|---|---|---|
| Brass | ? | Malleable, corrosion-resistant | Musical instruments, decorative items |
| Bronze | ? | Hard, low friction | Bearings, statues, medals |
| Stainless steel | ? | Corrosion-resistant, strong | Kitchen utensils, surgical instruments |
| Duralumin | ? | Lightweight, strong | Aircraft parts |
| Nichrome | ? | High resistance to heat | Heating elements |
(a) Complete the table by filling in the composition of each alloy.
(b) Calculate the percentage of carbon in steel that contains 0.5% carbon by mass. If you have 200 g of this steel, how many grams of carbon does it contain?
(c) Bronze contains 88% copper and 12% tin. Calculate the mass of copper and tin in a 5 kg bronze statue.
(d) Duralumin contains 95% aluminium, 4% copper, 0.5% manganese, and 0.5% magnesium. Why is aluminium the major component? What role do the other metals play?
(e) A company wants to make 1000 kg of brass containing 70% copper and 30% zinc. Calculate the mass of each metal required.
Q17. Interstitial compounds have the following characteristics:
They are very hard
They have high melting points
They retain metallic conductivity
They are chemically inert
(a) Explain each of these properties based on the structure of interstitial compounds.
(b) TiC (titanium carbide) has a melting point of 3160°C while Ti metal melts at 1668°C. Why is TiC's melting point so much higher?
(c) Hydrogen forms interstitial hydrides with transition metals like Pd, Ni, and Pt. These are used for hydrogen storage. Why can transition metals absorb large volumes of hydrogen?
(d) A hydrogen storage tank using palladium hydride (PdHₓ) can store hydrogen at a density higher than liquid hydrogen. If x = 0.6 in PdHₓ, calculate the mass percentage of hydrogen in this compound. (Atomic masses: Pd = 106.4, H = 1)
(e) Why are interstitial hydrides being researched as future fuel storage materials for hydrogen-powered vehicles?
Q18. In a school project on "Metals in Everyday Life," students survey their homes for alloys and interstitial compounds.
(a) A student finds that her mother's brass utensils (pital bartan) have been in the family for generations. Why does brass not rust like iron? What gives brass its golden colour?
(b) Another student notices that his bicycle has ball bearings made of steel. Why are ball bearings made of steel rather than pure iron? What property of steel makes it suitable?
(c) A third student finds that her father's wristwatch has a stainless steel back. Why is stainless steel used instead of ordinary steel? What elements are added to make it "stainless"?
(d) The students learn that Indian 10-rupee coins are made of a copper-nickel alloy. Why is this alloy chosen for coins? (Consider properties like durability, corrosion resistance, and appearance.)
(e) The teacher asks: "If you were designing a bridge for a coastal city like Mumbai, which alloy would you choose for the structural framework and why?" Give your answer with specific reasons.