Chemistry Fundamentals & pH simulations Flashcards
Describe the properties of ionic and covalent bonds including their relative strength and what happens to the electrons in each bond type
Ionic bonds = One atom transfers an electron to another atom that takes it, they are usually strong but can become weaker in water due to water separating atoms
Covalent Bonds = atoms share one or more electrons, they are strong and stable, especially in living things, water has no affect
Define ion
a charged atom that has gained or lost electrons, making it either positive or negative
Define cation
a postive ion
Relate Hydrophobic to how they interact with water
“afraid of water” these substances DONT mix with water and usually stay separate, they typically lack charges or polar groups
Define anion
a negative ion
Relate Polar to how they interact with water
Molecules with areas of positive and negative charge due to uneven electron distribution
Relate Hydrophilic to how they interact with water
“loving of water” these substances DO mix well with water, often have charges or polar groups that attract water molecules
Relate Non-polar to how they interact with water
have no significant charge differences
Diagram the chemical structure of water
H
\
O
/
H
Indicate the positive and negative regions of water
Positive region= hydrogen atoms have a slight positive charge because they don’t hold the shared electrons with oxygen very tightly
Negative region= oxygen atom has a slight megative charge because it holds the electrons more tightly than hydrogen atoms
Describe the type of chemical bonds that join atoms with an individual water molecule
Covalent bonds
Describe the type of chemical attractions that exists between different water molecules in a beaker of liquid water
Hydrogen bonding helps water molecules stick together and give water special properties
Describe the key features of the pH scale
the pH scale measures how acidic or basic (alkaline) a solution is
Describe which ions are important in determining the pH value of a solution
Hydrogen (H) and hydroxide (OH-)
More H ions means a lower pH (acidic) while more OH- means a higher pH (basic)
Define Acid
a substance that can donate hydrogen ions (H*) when it dissolves in water
Define Base
a substance that can accept hydrogen ions (protons) or donate hydroxide ions (OH-) in a solution
Describe what it means for a solution to be neutral
a neutral solution has equal amount of hydrogen ions (H*) and hydroxide ions (OH-) so it’s neither acidic nor basic
Relate pH to proton (H+) concentration
As OH- increases, H* decreases and vice versa
Describe the purpose of a buffer
helps keep the pH of a solution stable
State the pH value of human blood
typically around 7.35 to 7.45
