Properties of Water
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Water can absorb or lose a large amount of heat without changing temperature very quickly. What is this property of water called?
High heat capacity
What are the atoms in a molecule of water?
2 hydrogen atoms and 1 oxygen atom
What is surface tension?
The strength of water’s surface caused by attraction between water molecules that allows small objects (like insects or paper clips) to stay on top of water
Solid water is ______________ than liquid water
How are water striders able to walk on water?
They don't break the surface tension of the water as they walk
What kind of molecules can water dissolve?
Polar molecules
The hydrogen end of water has what charge?
slight positive charge
Why is water able to dissolve more substances than other liquids?
It comes from its polarity: The slightly negative oxygen end is attracted to positive charges and the slightly positive hydrogen ends are attracted to negative charges
Water sticking to other surfaces/substances is known as
Adhesion
At higher elevation, what happens to the boiling point of water?
The boiling temperature decreases
Water is known as a _______________________ because it can dissolve more substances that most liquids
Universal Solvent
The oxygen end of a water molecule has what charge?
slight negative charge
Water sticking to other water molecules is known as?
Cohesion
What are four properties of water?
1. Cohesion
2. adhesion
3. Water is a versatile solvent
4. Water has a high heat capacity
5. Water's expansion upon freezing
What can break up hydrogen bonds effectively?
Hint: Think of soap
Surfactants
What overall charge does a water molecule have?
Neutral or No charge
What kind of charges attract?
Opposites: a positive and a negative
This causes water to clump together in drops.
cohesion
What causes water's polarity?
The charges are unevenly distributed --> the molecule has two different “ends” — one slightly negative and one slightly positive
In order for a gram of water to evaporate, what temperature (oC) must be reached and how many calories must be gained?
100oC and 540 cal/gram
Capillary action is made possible due to which two properties of water?
Cohesion and adhesion
What are hydrogen bonds?
Weak attractions between the slightly positive hydrogen (δ+) of one water molecule and the slightly negative oxygen (δ–) of another water molecule
Why is solid water less dense than liquid water?
When water freezes, the molecules spread out and form a more open structure. Hydrogen bonds lock water molecules into a rigid, crystal structure
Is water evaporation slow or fast?
Slow. The hydrogen bonding is very hard to break apart resulting in a slow evaporation process
What role does water play in making the Earth warm enough to live on?
Water vapor absorbs the heat from the sun and holds onto it to form a global "blanket"