Assertion and reason

Exercise and reference answers

Questions

1. Reason

   A single Lewis structure sometimes cannot describe the molecule accurately.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Resonance structures are written for some molecules.

2. Reason

   A crystal lattice is stabilised by the enthalpy of lattice formation.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Ionic compounds have high melting points.

3. Reason

   A Lewis structure shows both bonded pairs and lone pairs.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   Lone pairs form bonds.

Explanation