2.01 Properties of Water
Why is it important to ecosystems that ice floats in liquid water?
- floating ice helps to insulate water, allowing for like underneath to continue - if water was denser than ice, then lakes and ponds would freeze from the bottom up, killing marine life and ecosystems
capillary action
- the movement of water through a narrow tube - occurs when cohesion, adhesion, and surface tension work together
pH scale range
0-14
pH of water
7
density
a ration of mass to volume
pH less than 7
acids
What are the two main types of chemical bonds?
ionic bonds and covalent bonds
What happens when water freezes?
it expands and the molecules form rigid hexagon-like structures
example of an acid
lemon juice, vinegar
example of a base
liquid drain cleaner
specific heat
the amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius
ionic bond
the attraction between a positively charged atom and a negatively charged one
surface tension
the measure of how difficult it is to stretch or break the surface of a liquid
Why is ice less dense than water?
the specific hexagonal arrangement of the molecules in ice
vaporize
to convert a substance from a liquid to a gas
example of adhesion
water adhering to the side of a beaker
example of cohesion
water beading up on a leaf
example of surface tension
water bugs, overfilling a glass
Does water have a high heat of vaporization?
yes, because it has a high specific heat
Does water have a high specific heat?
yes, meaning that it can absorb and release large amounts of heat with only small changes in temperature
What is the chemical formula for water?
H₂O
heat of vaporization
The amount of heat energy needed to convert 1 gram of liquid to a gas
covalent bond
atoms are held together by mutual attraction for shared electrons
covalent compound
atoms that are covalently bonded
ionic compound
atoms that are ionically bonded together
adhesion
attraction between molecules of different substances
cohesion
attraction between molecules of the same substance
pH more than 7
bases
Why is water considered to be a universal solvent?
because many different substances dissolve well in water
Why does water have a high boiling point?
because of hydrogen bonding that holds H2O molecules together
What does pH measure?
concentration of hydrogen ions
What type of bond forms water?
covalent