Midterm Exam 3

Question 1

chemical reactions

Answer 1

• represented by chemical equations
• shows relationship between reactants&raquo_space;> products
• involves breaking & forming of bonds (can be covalent or ionic)

Question 2

what are the rules to balancing a chemical equation?

Answer 2

• CANNOT add new reactants or products
• CANNOT change formula of a reactant or product
• coefficients are REDUCED to the SMALLEST WHOLE NUMBERS

Question 3

what are the four types of chemical reactions?

Answer 3

1. synthesis (condensation)
2. decomposition
3. single replacement
4. double replacement

Question 4

synthesis

Answer 4

• also known as CONDENSATION
• example: A + B = C

Question 5

decomposition

Answer 5

• opposite of synthesis
• example: AB = A + B

Question 6

single replacement

Answer 6

• single exchange only
• example: A+ BC = AC + B

Question 7

double replacement

Answer 7

• double exchange
• example: AB + CD = AD + CB

Question 8

how is water involved in terms of chemical reactions?

Answer 8

• has many interactions in both chemistry and biochemistry
• HYDROLYSIS: water (hydro) is being used to SPLIT (lyse) a molecule
• acid (hydrogen ions H+) catalyzes hydrolysis of an ester - turns into a carboxylic acid

Question 9

hydration

Answer 9

process where water IS ADDED to a double bond (within an ALKENE) in the presence of an ACID (H+) to form an ALCOHOL

Question 10

dehydration

Answer 10

• the oppostive of hydration
• process where ALCOHOL LOSES WATER in the presence of an ACID (H+) *and heat to form an ALKENE

Question 11

reduction

Answer 11

• the GAIN of ELECTRONS
• the LOSS of OXYGEN
• the GAIN of HYDROGEN

Question 12

oxidation

Answer 12

• the LOSS of ELECTRONS
• the GAIN OF oxygen
• THE LOSS OF HYDROGEN

Question 13

redox

Answer 13

meaning that reduction and oxidation ALWAYS OCCUR TOGETHER

Question 14

combustion

Answer 14

specific oxidation reaction: when oxygen reacts with ORGANIC chemicals
- will always produce carbon dioxide & water

Question 15

what do the alcohols oxidize into?

Answer 15

primary alcohols - ALDEHYDES
secondary alcohols - KETONES
tertiary alcohols - DOES NOT OXIDIZE
*aldehydes can oxidize into carboxylic acids

Question 16

catalytic hydrogenation

Answer 16

hydrogen gas can be added to a double bond (alkene) in the presence of platinum (going from unsaturated to saturated)

Question 17

what are the gas properties?

Answer 17

• gases behave similarly regardless of their nature
• gas particles DO NOT interact with one another
• FREE to move about a container
• they COLLIDE with container walls: makes PRESSURE

Question 18

pressure

Answer 18

the force of collisions that take place between gas particles and an object

Question 19

what are factors we have to consider in regards to pressure?

Answer 19

volume & temperature
GREATER VOLUME, PRESSURE DOWN
LOWER VOLUME, PRESSURE UP
GREATER TEMP, PRESSURE UP
LOWER TEMP, PRESSURE DOWN

Question 20

atmospheric pressure

Answer 20

refers to the force applied on the earth’s surface

Question 21

what are some important units to remember in terms of atmospheric pressure (what is the standard temperature & pressure)?

Answer 21

1 mmHg = 1 torr
1 atm = 760 torr = 760 mmHg

Question 22

vapor pressure

Answer 22

when a liquid is placed in a closed container: will begin to EVAPORATE until a maximum pressure is reached
- changes with TEMPERATURE

Question 23

boiling point

Answer 23

temperature when a liquid’s vapor pressure = atmospheric pressure

Question 24

Boyle’s Law

Answer 24

P1V1 = P2V2
(inital) (final)

Question 25

mixtures

Answer 25

contains two or more substances

Question 26

homogeneous mixtures

Answer 26

UNIFORMLY DISTRIBUTES the substances they contain - these are also called SOLUTIONS!!!

Question 27

heterogeneous mixtures

Answer 27

DOES NOT uniformly distribute the substances they contain

Question 28

solvent

Answer 28

the component present in the greatest amount (water)

Question 29

solute

Answer 29

the component dissolved in the solvent (sugar dissolving in water)

Question 30

how does a solution form?

Answer 30

- both solute and solvent particles are around the same size - both have to INTERACT with each other - interactions are NON-COVALENT (ionic bonds, dipole-dipole bonds, hydrogen bonds)

Question 31

like dissolves like

Answer 31

can help predict if the substance is soluble or insoluble

Question 32

solubility

Answer 32

the amount of solute that will dissolve in a solvent at a given temperature

Question 33

what happens when two homogenous mixtures react together?

Answer 33

they form a solid PRECIPITATE

Question 34

alkanes (hydrocarbons)

Answer 34

will EASILY MIX, but DO NOT DISSOLVE in water

Question 35

nonpolar hydrocarbons

Answer 35

cluster together through LONDON FORCES

Question 36

polar hydrocarbons

Answer 36

cluster and interact through H-BONDING

Question 37

how are biochemical compounds classified?

Answer 37

- HYDROPHILIC: love water - compounds soluble in water - HYDROPHOBIC: hate water - compounds insoluble in water - AMPHIPATHIC: compounds that have both hydrophilic/phobic parts

Question 38

hydrophilic

Answer 38

- often have compounds that resemble water - form typical H-BONDS

Question 39

hydrophobic

Answer 39

- these are basic FATTY ACIDS that have long hydrocarbon chains

Question 40

amphipathic

Answer 40

- can be originated from hydrophobic fatty acids with the added conversion of NaOH

Question 41

amphipathic nature

Answer 41

- nonpolar interior: hydrophobic - polar exterior: hydrophilic

Question 42

concentration

Answer 42

refers to the amount of solute that is dissolved in a solvent

Question 43

saturated concentration

Answer 43

solvent that holds the MAXIMUM amount of solute that can be dissolved at a particular temp

Question 44

unsaturated concentration

Answer 44

holding LESS than a saturating amount of solute within a solvent

Question 45

what are the calculations for concentration?

Answer 45

1. weight/volume % = g of solute/mL of solution x 100 2. volume/volume % = mL of solute/mL of solution x 100 3. weight/weight % = g of solute/g of solution x 100

Question 46

molarity

Answer 46

commonly used to report concentration

Question 46

what are the formulas for concentration?

Answer 46

ppt = g of solute/mL of solution x 10^3 ppm = g of solute/mL of solution x 10^6 ppb = g of solute/mL of solution x 10^9

Question 46

M equivalent

Answer 46

g of solute/L of solution

Question 47

equivalent (eq)

Answer 47

number of moles of charges that one mole of a solute contributes to a solution

Question 48

dilution

Answer 48

easy way to reduce the concentration of a solution by adding more solvent V(original) x C(original) = V (final) x C(final)

Question 49

suspensions

Answer 49

contains large particles suspended in a liquid - VISIBLE particles to the naked eye - will SETTLE due to gravity after enough time - can be separated from the liquid

Question 50

colloids

Answer 50

contains larger particles larger than solutions but SMALLER than suspensions - NON-VISIBLE particles to the naked eye - will NOT SETTLE upon standing

Question 51

diffusion

Answer 51

substances move from areas of higher concentration to areas of lower concentration

Question 52

semipermeable membranes

Answer 52

allow only SOLVENTS (water) to pass through while SOLUTES cannot pass

Question 53

solvent molecules (diffusion)

Answer 53

pass from side of lower solute concentration to the side of higher solute concentration to reach equilibrium

Question 54

osmosis

Answer 54

net movement of water from a solution of lower concentration to a solution of higher concentration

Question 55

blood plasma concentration

Answer 55

isotonic - same concentration inside and outside the cell hypertonic - greater concentration with water flowing OUT (crenation) hypotonic - lower concentration with water flowing IN (hemolysis)