Acids & Bases
Considered a 'neutral' pH
*double pts if you give how high and low the basic/acid levels get*
What is a pH of 7?
*max basic=14 max acidity= 0*
Water makes up what % of the body?
70%
What is the basis of life? Where did life evolve?
What is Water? an aqueous solution!
True or False?
Warm weather near beaches in the wintertime is an example of 'Evaporative Cooling'
False
A measure of how hard it is to break the surface of a liquid
What is Surface Tension?
What two ions does water dissociate into?
hydrogen ions (H+)
hydroxide ions (OH-)
What is forming the Hydrogen Bond between 2 water molecules?
-How are they attracted to each other?
Partial positive and partial negative charges are attracted to each other
How do 'buffers' work?
They can accept (H+) through a chemical reaction. They can reverse the same reaction to donate (H+) to a solution.
Give one way that water can dissolve a solute
*bonus 100 if you can give both*
1. forms a hydrogen shell
2. making hydrogen bonds
amt. of heat needed to change a substance from liquid to gas form
What is 'Heat of Vaporization'?
What does (H+) truly represent?
the formula for a 'hydronium ion'
H3O+
This is how water moves upwards in tall trees, seemingly defying gravity
Evaporation, with help from Cohesion
What part of an H2O molecule (Mickey's ears or his head) would form a hydration shell around the sodium (Na+) in a salt molecule?
The partially negatively-charged Oxygen (his head).
What form of H2O am I describing?:
-hydrogen bonds are at max length (stable)
-less dense, less movement
-insulating qualities
What is H2O in its Solid form?
the amount of heat needed to raise the temperature of 1 gram of a substance 1 degree Celsius (°C).
What is Specific Heat?
A solution has a pH of 9. What is the hydroxide ion (OH-) concentration?
10-5M
List 3 of 4 'emergent properties' of water.
1. cohesive behavior
2. ability to moderate temperature
3. expansion upon freezing
4. versatility as a solvent
Explain how 'Ocean Acidification' occurs
CO2 from burning fossil fuels (25%) gets absorbed by the ocean, creating carbonic ACID
*will changing the pH an organism lives in be beneficial for that organism?*
What were the 2 examples given that explain why Cohesion is so important?
1. It allows water to travel up plants
2. It creates surface tension
a substance that minimizes changes in the concentration of pH
What is a Buffer?
Mixing baking soda and vinegar is actually 2 chemical reactions. What are they?
acid-base reaction followed by a decomposition reaction
Describe the difference between 'cohesion' and 'adhesion'.
Cohesion refers to how water can stick to water.
Adhesion refers to water sticking to anything else.
Explain how baking soda is a base and a buffer
It is a base because it can accept hydrogen ions (H+).
It is a buffer because it can create carbonic acid (a buffer)
Explain the difference between a 'solution', a 'solvent', and a 'solute'.
solution- a mixture that is a homogenous mixture of substances
solvent- the dissolving agent
solute- what is being dissolved
the energy that an object possesses due to its motion
What is Kinetic Energy?