Structure of Water and Hydrogen Bonding

Water is...

• Polar

• Nonpolar

Water molecules require a lot of energy to break the hydrogen bonds.  This gives water a high

• density

• polarity

• solvency

• specific heat

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which of the following properties of water enables molecules to cling together as they move from the roots to the leaves of plants?

• Water expands as it freezes.

• Water is an excellent solvent.

• Water exhibits cohesive behavior.

• Water moderates temperature.

Why does ice float?

• As water freezes, it expands and its density decreases.

• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.

• As water freezes, air becomes trapped between the hydrogen bonds of water molecules.

• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.

The property of water that allows water molecules to stick to another substance is

• adhesion

• cohesion

• density

• specific heat

Tags

NGSS.MS-ESS2-4

Many fish and aquatic plants can survive a cold winter because the layer of ice that forms at the top of the lake insulates the water below and prevents the lake from freezing solid. What unique property of water contributes to this effect?

• Water absorbs heat when it evaporates and forms a gas

• Water expands and becomes less dense when it freezes.

• Water molecules completely separate into ions in solutions.

• Water forms hydrogen bonds with ions and other polar substances.

Tags

NGSS.HS-ESS2-5

A florist places a bouquet of white carnations in water containing blue dye. After a time, the flowers turn blue. What process helped the carnations to change color?

• Specific heat 

• Surface tension

• Cohesion and adhesion of water molecules 

• Formation of covalent bonds between hydrogen and oxygen molecules

Tags

NGSS.MS-PS1-2

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

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

• it forms ionic bonds with ions, hydrogen bonds with polar molecules, and hydrophobic interactions with non polar molecules

• it forms hydrogen bonds with itself so cohesion is possible

• it is liquid and will adhere to many substances

Which of the following effects is produced by the high surface tension of water?

• Lakes don't freeze solid in winter, despite low temperatures.

• A water strider can walk across the surface of a small pond.

• Organisms resist temperature changes, although they give off heat due to chemical reactions.

• Water can act as a solvent.

• The pH of water remains exactly neutral

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

• water's change in density when it condenses

• water's ability to dissolve molecules in the air

• the release of heat by the formation of hydrogen bonds

• the absorption of heat by the breaking of hydrogen bonds

• water's high surface tension

Tags

NGSS.MS-PS3-5