Allotropes of Carbon - UNSOLVED PRACTICE SET
Chapter: Carbon and Its Compounds | Topic: Allotropes of Carbon
ALLOTROPES OF CARBON - UNSOLVED PRACTICE SET
Topic: Allotropes of Carbon
Multiple Choice Questions
Q1. Which of the following is NOT an allotrope of carbon?
- Diamond
- Graphite
- Coal
- Buckminsterfullerene
Q2. In diamond, each carbon atom is bonded to:
- 2 other carbon atoms
- 3 other carbon atoms
- 4 other carbon atoms in a tetrahedral arrangement
- 6 other carbon atoms
Q3. Graphite is a good conductor of electricity because:
- It has free electrons in its structure
- It is very hard
- It has a high melting point
- It is transparent
Q4. Buckminsterfullerene (C₆₀) has a structure similar to:
- A flat sheet
- A football (soccer ball)
- A diamond crystal
- A chain of carbon atoms
Q5. Which allotrope of carbon is used as a lubricant in heavy machinery?
- Diamond
- Graphite
- Fullerene
- Charcoal
Q6. The main difference between diamond and graphite is:
- Their chemical composition
- The number of carbon atoms
- The arrangement and bonding of carbon atoms
- Their colour
Short Answer Questions
Q7. Why is diamond used in cutting tools and drill bits, despite being very expensive?
Q8. Explain why graphite is used in making electrodes for dry cells, while diamond cannot be used for this purpose.
Q9. Your art teacher uses charcoal pencils for sketching. Charcoal is also an allotrope of carbon. How is charcoal different from diamond in terms of structure and bonding?
Q10. What is fullerene? Mention one unique property of fullerene that makes it different from diamond and graphite.
Q11. Why does graphite feel slippery to touch? Explain with reference to its layered structure.
Q12. Both diamond and graphite have very high melting points. Explain the reason behind this similarity.
Long Answer Questions
Q13. Draw the structure of diamond and graphite. Explain how the difference in bonding and arrangement of carbon atoms leads to the following contrasting properties:
(a) Diamond is the hardest natural substance, while graphite is soft and slippery.
(b) Diamond is a non-conductor of electricity, while graphite is a good conductor.
Q14. Describe the structure of Buckminsterfullerene (C₆₀). How does its structure differ from both diamond and graphite? Mention any two potential applications of fullerenes in science and technology.
Q15. During a visit to a jewellery shop with your mother, you notice that diamond sparkles brilliantly, while the graphite in your pencil lead is dull and black. Explain the scientific reason behind this difference in appearance, connecting it to the internal structure of each allotrope.
Numerical / Application-Based Problems
Q16. A chemistry teacher asks students to compare the number of carbon atoms bonded to each carbon atom in diamond and graphite.
(a) How many C—C bonds does each carbon atom form in diamond?
(b) How many C—C bonds does each carbon atom form in graphite?
(c) If a diamond crystal contains 1000 carbon atoms, calculate the total number of C—C bonds present. (Hint: Each bond is shared between two atoms)
Q17. In a school science exhibition, a student displays models of diamond, graphite, and C₆₀ fullerene.
(a) Which model would have a three-dimensional network structure?
(b) Which model would show hexagonal rings in layers?
(c) If the student uses 60 plastic balls to represent C₆₀, how many pentagonal and hexagonal faces would the model have? (Recall: A football has 12 pentagons and 20 hexagons)
Q18. A company wants to manufacture two products:
Product X: Cutting tools for the construction industry
Product Y: Electrodes for electric batteries
The company has access to diamond, graphite, and charcoal.
(a) Which allotrope should be used for Product X and why?
(b) Which allotrope should be used for Product Y and why?
(c) Why would charcoal be unsuitable for both products?