Properties of Water

How many hydrogen bonds can one water molecule form at once?

Up to 4 hydrogen bonds.

Is water a hydrogen-bond donor, acceptor, or both?

Both a donor and an acceptor.

What is the molecular arrangement of water according to the review?

Tetrahedral arrangement with a bent shape and a net dipole.

True or false: Water has a bent trigonal planar arrangement.

False. Water has a tetrahedral arrangement, although the molecule has a bent shape and a net dipole.

Does water have a relatively high boiling point and melting point?

Yes.

Why is solid water (ice) less dense than liquid water?

In ice, hydrogen-bonded water molecules are locked into a spaced-out framework.

Why can liquid water pack more closely together than ice?

Liquid water molecules can tumble around freely and pack more closely together.

Why is melting ice thermodynamically favorable at a sufficiently high temperature?

Entropy increases when ordered solid ice becomes disordered liquid water, giving a favorable negative ΔG under the appropriate conditions.

Will NaCl likely dissolve well in water?

Yes; it is an ionic substance with charges.

Will ethanol likely dissolve well in water?

Yes; it is uncharged but polar.

Will wax likely dissolve well in water?

No; it is nonpolar and contains many hydrocarbons.

What does hydrophilic mean?

A substance is polar or charged and likes to interact with water.

What does hydrophobic mean?

A substance is nonpolar and does not like to interact with water.

What does amphipathic mean?

A molecule contains both polar and nonpolar regions.

What should you be able to determine by looking at a molecule's structure?

Whether it is hydrophilic, hydrophobic, or amphipathic.