Chemistry
Assertion (A): Naphthalene balls become smaller with the passage of time, as they sublime.
Reason (R): Naphthalene balls sublime, as such solids have stronger intermolecular forces of attraction in comparison to other solids.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
A is true but R is false.
Explanation — A is true as sublimable solids have weaker intermolecular forces of attraction in comparison to other solids. On heating, they acquire the kinetic energy of their vapour phase faster, and directly convert to the gaseous state without entering the liquid state.
R is false as substances that sublime (like naphthalene) have relatively weaker intermolecular forces, so particles can escape directly into the gas state.
Therefore, A is true but R is false is the correct option.
Related Questions
Assertion (A): Matter exists in three states; i.e. solids, liquids and gases.
Reason (R): The intermolecular forces of attraction and intermolecular spaces are different in different kinds of matter.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Liquid molecules can move freely and are able to occupy the whole space available to them.
Reason (R): The molecules of liquids have larger intermolecular spaces and weaker intermolecular forces of attraction than those in solids.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Conversion of a substance in solid state to its liquid state is called melting.
Reason (R): On heating, the kinetic energy of solid molecules increases.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Solids can be hardly compressed by applying pressure.
Reason (R): The molecules in solids are closely packed.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.