Polarity & Solvency
What type of bond connects hydrogen and water in one single molecule of water?
polar covalent bond
Water's ability to stick to itself.
cohesion
What is the name of the property that allows for water to travel upwards, against the flow of gravity?
capillary action
Water's ability to "hold onto" heat energy, before it changes temperature.
high heat capacity
This property explains why solid water floats on top of liquid water.
density (ice is less dense than water)
Polar molecules can only dissolve ________ molecules.
(other) polar
Water's ability to stick to OTHER molecules.
adhesion
What type of bond connects two different water molecules?
hydrogen bond
This property describes why it takes water a very long time to evaporate (change from l to g).
DOUBLE JEOPARDY: what temperature does water take to boil?
High heat of vaporization/evaporation
DOUBLE JEOPARDY: 212C or 100F
This property explains why certain bugs can walk/float on top of water.
surface tension
Show how water dissolves NaCl (salt).
Hint: Na + Cl -
H + combines with Cl -
O - combines with Na +
cohesion
Hydrogen bonds are ____ and this is why it is relatively easy to break the surface tension of water.
WEAK
What temperature does water freeze (turn from l to s)?
0C or 32F
When temperatures are freezing in the winter, ponds freeze from _______ to __________, so the animals and plants can still survive in liquid water.
TOP to BOTTOM
Water is known as the _________ solvent.
universal (because it can dissolve many things!)
When water sticks to the windows in the car on a rainy drive home, this is an example of...
adhesion
This is how capillary action works. Two properties (List them) work together, to allow for water to travel up small tubes in plants, against gravity.
cohesion + adhesion
Water can absorb a lot of heat before its temperature changes. What property of water allows it to do this, and why is this important for living things?
high heat capacity — it helps organisms and environments maintain stable temperatures even when the surroundings change
When water freezes, it expands instead of contracting. How does this change affect its density compared to liquid water?
ice becomes less dense than water (crystal structure) so it floats
Water can dissolve many different substances. Explain how water’s polarity makes it such a good solvent.
Water has both + and - charges, with H and O, respectively. This allows for it to combine with and dissolve other substances with both - and + charges.
Water can move upward through your straw in your cup. Which two properties of water make this possible, and how do they work together?
cohesion and adhesion: the water sticks to itself and the insides of the straw as it travels up to your mouth
Water moves through the tiny xylem tubes in plants because of capillary action. How do hydrogen bonds make this process possible?
hydrogen bonds cause water molecules to stick together (cohesion) and to the tube walls (adhesion), allowing water to climb upward through capillary action
When humans sweat, the water on their skin absorbs heat energy and then evaporates, cooling the body. Which property of water causes this effect, and how does it work?
high heat of vaporization — it takes a lot of energy to break hydrogen bonds and turn liquid water into vapor, carrying heat away from the body
When you slightly overfill a glass of water, the surface forms a rounded shape above the rim without spilling. Which property of water causes this effect, and what type of bond creates it?
Surface tension, this is created because of cohesion, by hydrogen bonds.