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