AP Chemistry Unit 2 Review

Front

What type of overlap forms pi bonds?

Back

Side to side overlap of p orbitals.

Front

Which molecule is polar despite having polar bonds: CCl4, CO2, NH3, or CH4?

Back

NH3.

Front

Breaking bonds is _____________. Forming bonds is _____________.

Back

Endothermic; exothermic.

Front

Calculate the enthalpy change for the reaction: H2O2(g) → H2O(g) + ½O2(g) given average bond enthalpies for O-O and O=O are 146 and 496 kJ/mol respectively.

Back

-102 kJ.

Front

What does the resonance structure of C6H6 indicate about the bonds between carbon atoms?

Back

All the bonds between the carbon atoms have the same length.

Front

Define a polar molecule.

Back

A molecule that has a net dipole moment due to the presence of polar bonds and an asymmetrical shape.

Front

What is the difference between endothermic and exothermic reactions?

Back

Endothermic reactions absorb heat, while exothermic reactions release heat.

Front

What is bond enthalpy?

Back

The amount of energy required to break one mole of a bond in a gaseous substance.

Front

Explain the concept of resonance in chemistry.

Back

Resonance describes the situation where a molecule can be represented by two or more valid Lewis structures.

Front

What is the significance of bond length in a molecule?

Back

Bond length affects the strength and stability of the bond; shorter bonds are generally stronger.