Semester 1 Ahs 131 Lecture Test

Front 1

Where are protons found?

Back 1

Nucleus

Front 2

Where are neutrons found?

Back 2

Nucleus

Front 3

Where are electrons found?

Back 3

Outside the nucleus in shells that make up the elctron cloud

Front 4

What does the atomic number represent?

Back 4

The number of protons

Front 5

What does the atomic mass represent?

Back 5

The total number of protons andneutrons in the nucleus

Front 6

Electrons are found occupying what regions of the atom?

Back 6

Electrons occupy the outside of the atom called an electron cloud and are divided into shells

Front 7

Electron Shells

Back 7

Electron shells are subdivided into subshells
Subshells are sm p, d, f

Front 8

Covalent Bonding

Definition

Back 8

Sharing of electrons between atoms
Atoms that bond covalently have a difference in electronegativity less than 1.7

Front 9

Ionic Bonding

Definition

Back 9

Also called electrovalent or noncovalent bonding
Characterized as a charge-charge interaction
Defined as a transfer of electrons
Occurs when electronegativity difference is 1.7 or greater

Front 10

Hydrogen Bonding

Definition

Back 10

A type of non-covalent bond

Bonding occurs between a positive H from one molecule and a negatively charged oxygen or nitrogen from another molecule

Front 11

Electronegativity

Definition

Back 11

The attractive force between an atom's positively charged protons and its negatively charged electrons
The force of attraction an atom exhibits for its electrons

Front 12

Electronegativity

How does it influence bonding?

Back 12

When the electronegativity difference is:
0.0 - 1.6 bond is covalent
0.0 - 0.4 electrons are shared equally - non-polar
0.5 - 0.9 electrons are shared unequally - non-polar if molecule is symmetrical
1.0 -1.6 electrons are shared unequally - polar if moleucle is asymmetrical
1.7 and greater bond is ionic and electrons are transferred

Front 13

Reactions

Back 13

Exchange reaction
Reversible reaction
Synthesis reaction
Decomposition reaction

Front 14

Exchange Reaction

Example

Back 14

HCl + NaOH NaCl (salt) + H2O (water)

Front 15

Reversible Reaction

Example

Back 15

H2O + CO2 H2CO3 (carbonic acid)

Front 16

Synthesis Reaction

Example

Back 16

N + 3H NH3 (ammonia)

Front 17

Decomposition Reaction

example

Back 17

CH4 (methane) C (carbon) + 4H (hydrogen)

Front 18

Define pH

Back 18

pH represents the amount of free H+ ions present in solution

Front 19

pH

Back 19

the lower case "p" in mathematics represents the negative logarithm (-log), which is based on 10 to a negative power or exponent
Ex: 10-3 equals .001, or one-thousandth of one, the one representing 1 mole
Tghe lower the pH the higher the concentration of free hydrogen ions H+ and the more acidic

Front 20

pK

Back 20

Represents the amount of ionization product at equilibrium

Front 21

Why is water an excellent solvent?

Back 21

Water is an excellent solvent because of its tendency to form H bonds, and its dipolar character.

Front 22

Water as a solvent

Back 22

H Bonds - Water can form hydrogen bonds, and therefore readily dissolve hydroxyl compounds, amines, sulfhydryl compounds, esters, ketones, and a wide variety of other organic compounds

Front 23

Water as a solvent

Back 23

Dipolar character allows it to dissolve ionic compounds
The interaction of dipoles with cations and anions causes the ions to become hydrated - that it, surrounded by the polar water molecules(called hydration shells)
The high dielectric constant helps dissolve ionic compounds
Dipolar nature of water also helps to dissolnonionic, but polar organic molecules such as amides

Front 24

Dielectric Constant

Back 24

get definition
water has a high dielectric constant

High dielectric constant results from dipole character of the water molecule
High dielectric constant reduces electrostatic forces between other charged particles, so the molecules drift fruther apart and can dissolve in water

Front 25

Important characteristics of water

Back 25

Molecular weight is 18 gram/mol
Boiling point is 100 C
Freezing Point is 0 C
High viscosity
High surface tension
High dielectric constant

Front 26

Why does water freeze from the top down?

Back 26

liquid water is denser than solid ice
Liquid water is denser than ice because when the ice lattice breaks down, the molecules can move closer together

Front 27

How does the lattice of ice differ from the lattice of liquid water

Back 27

Ice has a tetrahedral lattice - each water molecule is hydrogen bonded to 4 other water molecules - this creates rigid OH vectors
Ice has a closed lattice (clathrate)
Water - The lattice is partially broken down in water - bonds form and break, so you have an open lattice as ice melts
see pic pg. 6

Front 28

Why does ice expand?

Back 28

the secret lies in the rigid OH vectors create when a water molecule interacts with 4 other water molecules
Ice expands because the molecules can move further apart (same reason it is less dense than liquid water)

Front 29

Molecular formula of monosaccharides

Back 29

C6H12O6
Glucose
Fructose
Galactose
Isomers of one another
Same molecular formula

Front 30

Maltose

Back 30

Glucose + Glucose

Front 31

Lactose

Back 31

Glucose + Galactose

Front 32

Sucrose

Back 32

Glucose + Fructose

Front 33

Pentoses

Back 33

5 carbon sugars
Ribose
Deoxyribose

Front 34

Ribose vs Deoxyribose

Back 34

find molecular differences

Front 35

Which nucleic acids contain ribose and deoxyribose?

Back 35

Deoxyribose is is DNA
Ribose is in RNA

Front 36

What is the composition of simple lipids?

Back 36

fatty acid + glycerol

Front 37

Fatty Acids

Back 37

Fatty acids are organic because they contain a carboxyl group (COOH)

Front 38

Compound Lipids
(Compound Phospholipids)

Back 38

Choline Phospholipids
Aminophospholipids
Sphingophospholipids (sphingolipids)

Front 39

Compound Lipids

Back 39

Compound lipids are acyl glycerol that have in addition to fatty acids, other molecules attached to themselves