AP Water and Bonding Review

Which of the following hydrocarbons has a double bond in its carbon skeleton?

• C₃H₈

• CH₃

• C₂H₄

• C₂H₆

Answer explanation

Carbon always forms 4 bonds. With only 4 hydrogen available the carbon must form a double bond.

Water is made by 2 ​ (a)   atoms and 1 ​ (b)   atom bonded covalently together.

• hydrogen
• oxygen

When water vaporizes, what bonds are broken?

• ionic bonds

• hydrogen bonds between water molecules

• covalent bonds between atoms within water molecules

• nonpolar covalent bonds

The pH of a solution is based on the concentration of H⁺. Acidic solutions have a ​ (a)   pH and a ​ (b)   H⁺ concentration.

• low
• high
• medium

Answer explanation

Low pH = acid, high H+

High pH = base, low H+

Small insects can float on the surface of water. What makes this possible?

• the adhesive properties of water

• surface tension that is the result of the cohesive properties of water

• covalent bonds formed along the water's surface

• cohesive bonding between the insect and the water

Match the following temperatures:

• 37 ^oC

• freezing point

• 1 ^oC

• average human body temperature

• 100 ^oC

• boiling point

• 0 ^oC

• temperature change caused by a calorie of energy

Water is an excellent solvent. Select the answer that justifies this statement.

• As a polar molecule, it can surround and dissolve ionic and polar molecules

• It forms covalent bonds with ions, hydrogen bonds with polar molecules and hydrophobic interactions with nonpolar molecules

• It forms hydrogen bonds with itself so cohesion is possible

• It is a liquid and will adhere to many surfaces

Draw a hydrogen bond in the correct placement between the water molecules.

Coastal areas tend to have a more moderate climate compared to inland areas. What property of water makes this occur?

• High specific heat of water

• Water's lower density when frozen

• High solubility of water

• Cohesive and adhesive properties of water

Water is ​ (a)   because the electrons are shared unequally between the atoms that make up the molecule. The ​ (b)   has a negative charge and the ​ (c)   have a positive charge.

• polar
• oxygen
• hydrogens
• nonpolar
• carbon