Life 102 Chapter 2

Solid water is ___ dense than liquid water

less

What is the temperature of a substance a measure of?

How fast its molecules are moving

Gaseous Hydrogen is held together by a covalent bond and has no net

charge

If two atoms are joined by a polar covalent bond, the atom with the lower electronegativity will have a

positive charge

If an atom has 6 electrons in its outermost layer, how many covalent bonds must it form in order to have a stable outer shell of electrons?

2

Because polar water molecules attract each other, water is said to be

cohesive

Water carries two positive negative charges on the ____ atom and two partial positive charges, one on each ____ atom atom

oxygen, hydrogen

When 1g of sucrose is dissolved in 500 mL of water, the is the solvent and the ___ is the solute

water, sucrose

Molecules that are more polar tend to have

A higher specific heat A higher heat of vaporization

Capillary Action

Ability of water to rise inside a tube of narrow diameter against the pull of gravity

Hydrophobic substances tend to do the following

Assume shapes that minimize contact with water Aggregate together when mixed with water in order to minimize contact with water Repel water

Unlike covalent bonds, which produce a crystal lattice, ionic bonds are formed between 2 individual atoms, giving rise to true, discrete molecules.

False

A polar molecule

H2O

Water tends to repel or exclude which of the following

Nonpolar molecules Hydrophobic molecules

Heat of vaporization

The amount of energy required to change 1g of a substance from a liquid to a gas is called

The following statements about polar molecules are true

The distribution of electrical charge is uniform They are electrically neutral

Why does water rise inside a capillary glass tube?

Water molecules adhere to the surface of the glass

Which of the following accurately describes the cause of the high surface tension of water?

Water molecules attract each other

What does it mean when we say water is adhesive

it is attracted to other polar molecules and ions

The property of ___ heat measures the extent to which a surface resists changing its ___ when it absorbs or loses heat

specific, temperature

Because of the many hydrogen bonds that form between its molecules, water has a very high _______. This allows small insects to walk on water.

surface tension