CH301 - Unit 2 Exam 1

Front

What is resonance in chemistry?

Back

Resonance refers to the phenomenon where a molecule can be represented by two or more valid Lewis structures, indicating that the actual structure is a hybrid of these forms.

Front

Which compound exhibits resonance?

Back

CO₃²⁻ (carbonate ion) exhibits resonance due to its multiple valid Lewis structures.

Front

What is the shape of a tetrahedral molecule?

Back

A tetrahedral molecule has four bonds arranged around a central atom, forming a three-dimensional shape with bond angles of approximately 109.5°.

Front

What is the electronic geometry of NH₃ (ammonia)?

Back

The electronic geometry of NH₃ is tetrahedral, considering the three hydrogen atoms and one lone pair on nitrogen.

Front

How many lone pairs are present in PF₃ (phosphorus trifluoride)?

Back

PF₃ has one lone pair on the phosphorus atom.

Front

Which of the following is NOT an ionic compound: CaO, NaOH, BaCl₂, Br₂?

Back

Br₂ (bromine) is a diatomic molecule and not an ionic compound.

Front

Define ionic compound.

Back

An ionic compound is formed when atoms transfer electrons, resulting in the formation of positively and negatively charged ions that are held together by electrostatic forces.

Front

What is the bond angle in a tetrahedral molecule?

Back

The bond angle in a tetrahedral molecule is approximately 109.5°.

Front

What is the difference between electronic geometry and molecular geometry?

Back

Electronic geometry considers all electron groups (bonding and lone pairs), while molecular geometry considers only the arrangement of bonded atoms.

Front

What is a Lewis structure?

Back

A Lewis structure is a diagram that represents the bonding between atoms in a molecule and the lone pairs of electrons that may exist.