Unit 1: Biochemistry

What is the correct chemical formula for water?

• H₂O

• HO₂

• H₂O₂

• ₂H₁O

Water is a universal solvent because it...

• It can be found anywhere
• It freezes when it gets cold
• floats when frozen
• Dissolves most substances

Which of the following is an example of COHESION?

• water sticking to water

• water sticking to glass

• oil sticking to plastic

• hydrogen sticking to oxygen

Water is polar. What does that mean?

• it is a molecule with opposite charges on opposite ends

• it is a molecule with no charge

• it is a molecule with identical charges on opposite ends

• it is a molecule with too many protons

Water sticks well to many materials. What term relates to this property of water?

• cohesion

• adhesion

• density

• surface tension

Why does ice float?

• water expands when it freezes, making ice less dense than water

• water compacts when it freezes, making ice more dense than water

• hydrogen bonds in water push the ice to the surface

• ice is afraid of water, and avoids it

The attraction that causes water and other liquids to form drops on thin films is called ________________. This is also water’s ability to be attraction to other water molecules.

• adhesion
• capillary action
• cohesion
• surface tension

Large bodies of water do not quickly fluctuate in temperature. Why?

• Water is a solvent.
• Water has a high heat capacity.
• Water acts as a buffer.
• Water is non-polar.

Attractions between water molecules are called

• Covalent bonds
• Ionic bonds
• Polar bonds
• Hydrogen bonds

What kind of molecule is water?

• Ionic

• Polar Covalent

• Nonpolar Covalent

• Metallic