NEETChemistryp Block Elements (Group 13 & 14)
Assertion (A): Graphite is used as a dry lubricant in machines which run at high temperatures Reason (R): The layers of graphite slip one over the other when pressure is applied The correct option among the following is
Options
- A(A) is true but (R) is false
- B(A) is false but (R) is true
- C(A) and (R) are true. (R) is the correct explanation of (A)
- D(A) and (R) are true, but (R) is not correct explanation of (A)
Correct answer
C. (A) and (R) are true. (R) is the correct explanation of (A)
Step-by-step solution
Graphite is an allo rope of carbon that is soft and slippery due to which it is used as a lubricant. Thus, Assertion (A) is true. The reason for soft nature of graphite is the hexagonal layers of carbon atoms that slip over one another at high pressures. Thus, Reason (R) is true and it also explains the statement in assertion (A).