BSC 2010 CHAPTER 3: WATER AND LIFE EXAM
QUESTIONS AND 100% CORRECT ANSWERS
What element do the electron of the polar covalent bonds spend more time near in water
molecules?
Oxygen.
What does polarity do for water molecules?
It allows the water molecules to form Hydrogen bonds with each other.
What is a polar molecule?
A molecule with unequal sharing of electrons.
How many Hydrogen bonds can water form?
It can form less than or equal to 4 Hydrogen bonds.
What are the 4 emergent properties of water?
1) Cohesive Behavior
2) Ability to Moderate Temperature
3) Expansion upon Freezing
4) Versatility as a Solvent
What are the 4 emergent properties of water useful for?
They help facilitate an environment for life.
What is cohesion?
The attraction between different water molecules.
What does cohesion help with in plants?
It helps the transport of water molecules against gravity in plants.
What is adhesion?
The attraction between different substances.
What is surface tension?
A measure of how hard it is to break the surface of a liquid.
Why does water have a high surface tension?
The hydrogen bonding between the molecules at the air-water interface and to the water below.
What is Kinetic Energy?
, The energy of motion.
What is heat?
A measure of total kinetic energy due to molecular motion.
What is Temperature?
The intensity of heat due to average kinetic energy of molecules.
What is specific heat?
The amount of heat absorbed or lost when 1g of a substance changes temperature by 1 degree C.
Why does water have a high specific heat?
It has so many Hydrogen Bonds that need to be broken.
What is heat of vaporization?
The quantity of heat a liquid must absorb to convert 1g from liquid to gas.
What is evaporative cooling?
As a liquid evaporates, the surface of the liquid that remains behind cools.
What does water's high heat of vaporization help to do?
It helps moderate the climate.
Which is more dense, water as a liquid or solid?
The liquid for of water is more dense.
What does water do as it solidifies?
It expands instead of contracts.
When does water stop behaving like other liquids?
It stops after 4 degrees C.
When does water begin to freeze?
When its molecules are no longer moving vigorously enough to break their Hydrogen Bonds.
Why does ice float on water?
Ice is less dense than water.
What is a solution?
A liquid homogeneous mixture of two or more substances.
What is a solvent?
QUESTIONS AND 100% CORRECT ANSWERS
What element do the electron of the polar covalent bonds spend more time near in water
molecules?
Oxygen.
What does polarity do for water molecules?
It allows the water molecules to form Hydrogen bonds with each other.
What is a polar molecule?
A molecule with unequal sharing of electrons.
How many Hydrogen bonds can water form?
It can form less than or equal to 4 Hydrogen bonds.
What are the 4 emergent properties of water?
1) Cohesive Behavior
2) Ability to Moderate Temperature
3) Expansion upon Freezing
4) Versatility as a Solvent
What are the 4 emergent properties of water useful for?
They help facilitate an environment for life.
What is cohesion?
The attraction between different water molecules.
What does cohesion help with in plants?
It helps the transport of water molecules against gravity in plants.
What is adhesion?
The attraction between different substances.
What is surface tension?
A measure of how hard it is to break the surface of a liquid.
Why does water have a high surface tension?
The hydrogen bonding between the molecules at the air-water interface and to the water below.
What is Kinetic Energy?
, The energy of motion.
What is heat?
A measure of total kinetic energy due to molecular motion.
What is Temperature?
The intensity of heat due to average kinetic energy of molecules.
What is specific heat?
The amount of heat absorbed or lost when 1g of a substance changes temperature by 1 degree C.
Why does water have a high specific heat?
It has so many Hydrogen Bonds that need to be broken.
What is heat of vaporization?
The quantity of heat a liquid must absorb to convert 1g from liquid to gas.
What is evaporative cooling?
As a liquid evaporates, the surface of the liquid that remains behind cools.
What does water's high heat of vaporization help to do?
It helps moderate the climate.
Which is more dense, water as a liquid or solid?
The liquid for of water is more dense.
What does water do as it solidifies?
It expands instead of contracts.
When does water stop behaving like other liquids?
It stops after 4 degrees C.
When does water begin to freeze?
When its molecules are no longer moving vigorously enough to break their Hydrogen Bonds.
Why does ice float on water?
Ice is less dense than water.
What is a solution?
A liquid homogeneous mixture of two or more substances.
What is a solvent?
