embalming chemistry quiz 2

chapter 5-7

water’s role in the funeral home

water’s role in the funeral home

• it is the most common solvent (vehicle) used to dilute embalming fluid

• main participant in the process of decomposition via a reaction known as hydrolysis

general fun facts about water

• covers 71% of earth

• only 2.5% of earth’s water is fresh (98.8% ice, 1.2% liquid)

• babies are 65% water, adults are 60%

• 70% goes to agriculture

what is the molecular mass of water

18 amu, which is relatively small

is water polar or nonpolar

polar

what is hydrogen bonding

an attraction of each water molecule to another water molecule, like holding hands. hydrogen bonding and polarity of compounds creates attractions that initiate all the chemical reactions in our body.

features of hydrogen bonding

• hydrogen bonds are about 5% as strong as covalent bonds

• most prevalent between H and O

• can also exist between H and N as well as H and F

boiling point

the hydrogen bonds must first be broken, this takes energy which raises the boiling point

melting point

the hydrogen bonds in the crystal lattice must first be broken, this takes energy which raises the melting point

specific heat

• it takes a lot of energy to raise the temperature of water no matter what the temperature of water happens to be at the time.

• Water, due to hydrogen bonding, is able to withstand a significant addition of heat before its temperature raises

• Conversely, it does not give up its heat readily when the temperature cools. It stores its energy in the hydrogen bonds.

• Water protects our bodies from extreme temperature changes

surface tension

• caused by hydrogen bonding

• causes a meniscus to form in a graduated cylinder

• makes water skiing and swimming manageable

  • allows for a needle to float on water

facts about frozen water

• frozen water is less dense than its liquid form

• stacks like logs, gaps in the structure

• a glass of ice water, upon warming, is reduced in volume

hydrates

• hydrates are salts with water combined into its crystal structure in a definite ratio

• it’s an association not a combonation

• a reaction has not occured

  • Example: salt (CoCl2) + 6H2O = salt hydrate (CoCl2-6H2O)

desiccants

salts that hydrate readily with water in the atmosphere, like those “do not eat” packets

deliquescent

salts that hydrate to the point of disolving into a liquid

anhydrous

hydrated salts that are heated to the point of having their water removed (dehydrated)

efflorescent

hydrated salts that give up their water to the atmosphere upon standing

hydrates and their uses in funeral service

gypsum (plaster of paris) is used to fill in the skull following a cranial autopsy

hydrolysis

unlike hydration, hydrolysis is an actual chemical reaction with water, water splitting

water as a vehicle for embalmers

• most tap water has ions dissolved in it which creates what is commonly known as hard water (ions dissolved are often Ca2+, Mg2+, and sometimes Fe3+)

• issues created by hard water:

  • deposits on faucets and tile

  • diminished soap cleaning ability

  • coagulates and clots blood making it hard to inject embalming fluid

• the hardness is due to chloride or sulfate salts of calcium or magnesium

how do embalmers remedy permanent hard water?

• mask the effect (most common) by caging/sequestering Ca2+ and Mg2+ by organic chemicals present in embalming fluid. Ions aren’t removed but blocked from coagulating and clotting blood

• removing the ions

solutions

exist in one of two forms: homogenous (mixed in all proportions) and heterogenous (not completely mixed)

solute

that which gets dissolved

solvent

that which does the dissolving

solution definition

combination of dissolved and dissolving (solute + solvent + solution) and (embalming fluid + water = embalming solution)

solubility

the amount of solute that will dissolve in a specified amount of solvent

soluble/insoluble

refers to solids, will dissolve/won’t dissolve

miscible/immiscible

refers to liquids

how is solubility determined

by the nature of the solute and nature of the solvent, like dissolves like. (NaCl dissolves in water bc they’re both polar)

factors that influence solubility

• mixing (embalming machine)

• surface area (large chunks dissolve slower than small ones)

  • temperature (increasing temp doesn’t always increase solubility)

qualitative terms

not scientifically relevant but meaningful

dilute

well below the solubility point

concentrated

very near or at solubility point

unsaturated

any concentration before the solubility point

saturated

at solubility point

supersaturated

bayond solubility point

quantitative terms

scientifically relevant

two kinds of weight %

1. (mass of solute in grams / mass of solution in grams) x 100 = wt% by mass

   1. (mass of solute in grams / volume of solution in mLs) x 100 = wt% by volume

ratio

1: X ratio 1=mass of solute and X=mass of solution

ppm

(grams of solute / grams of solution) x 1,000,000

formaldehyde index

measured by amount of formaldehyde gas by mass in grams present in 100 mLs of solution (index 20 = 20g formaldehyde/100mLs)

• 5-15 = low index

• 16-24 = medium

  • 25-36 = high

macro effect

• solutes depress melting points and boiling points

  • diffuse-concentrated solutions, when mixed with dilute solutions, equilibriate (which can be sped up by stirring or temp)

osmosis

diffusion through a membrane (concentrated solution gets more dilute)

isotonic

two solutions of equal concentration

hypertonic

more concentrated than its partner

hypotonic

less concentrated than its partner

osmotic pressure

pressure necessary to stop osmosis

osmotic principles and the embalmer

• dehydrated bodies need moisture pumped into their cells, use an embalming fluid that is hypotonic compared to the cells, solution flows into cell

  • edematous bodies need moisture content removed from cells, use an embalming fluid that is hypertonic compared to the cells, liquid flows out of cell

acids, bases, and salts

• common in solutes

• biologically relevant

  • GI tract: - parietal cells in stomach secrete hydrochloric acid (pH1.5-3.5)

  • blood: pH 7.35

• found in dissolved water

self-ionization of water

• H2O + H2O = H3O+ + OH-

  • hydroxide (basic - OH-) and hydronium (acidic - H3O+)

• this reaction is reversible and only happens in a small amount

• equilibrium is reached

properties of acids

• sour taste (lemons)

• can be identified using acid-base indicator litmus paper which will turn red

• reacts with base to form water and salt

• react with carbonates/bicarbonates to liberate CO2/H2O/salt

• can exist in solid/liquid/gas

what does reacting with carbonates/bicarbonates to liberate CO2 and h2O and salt as an acid mean?

when an acid reacts with a carbonate/bicarbonate, it produces carbon dioxide gas (which you see as bubbles), water, and a salt. This happens because the acid's hydrogen ions displace the carbon in the carbonate, releasing carbon dioxide gas. The leftover parts then combine to form a new salt.

properties of bases

• bitter or caustic taste

• turns litmus paper blue

• feels slippery or soapy

• neutralizes acids (cavity fluid, dawn dish soap)

  • can be found in all physical states, but typically a moist oily solid

arrhenius theory

in water, acids are substances that produce hydrogen ions and bases produce hydroxide ions

bronsted-lowry theory

acid is a substance that donates a hydrogen proton to any substance, acid is a proton donor and a base proton acceptor

GN Lewis theory

acid = anything that accepts a pair of electrons

base = anything that donates a pair of electrons

amphoteric

a substance that can act as an acid or a base

example: water can act as an acid in the presence of a base and it can act as a base in the presence of an acid

zwitterion

a molecule with a seperate positive and negative charge

strengths of acids

strength is determined by % that a substance dissociates in aqueous solution.

strong acid = 60-90%, weak acid = 1-10%

strengths of bases

strength is determined by the percentage of a substance to dissociate into positive ions and hydroxide ions

what does pH stand for

power of hydrogen or potential of hydrogen

pH scale

a logarithmic scale denoting acidity of an aqueous solution

pH 7 is neutral (H+ = OH-)

pH < (less than) 7 is acidic (H+ > OH-)

pH > (more than) 7 is basic (H+ < OH-)

water is pH 7

what is the pH during life

~7.4

postmortem pH shift

• Immediately after death:

  • body is still metabolizing but metabolic waste isn’t being eliminated

  • pH becomes acidic

• Several hours after death

  • proteins breakdown in the body, nitrogen compounds are freed

  • pH becomes basic

• pH shift is not uniform across all body regions or tissues

what is the optimal pH range for embalming chemicals?

formaldehyde = 7.3 - 7.5

glutaraldehyde = 7.3-9.0

what do you do if the body pH isn’t within the optimal range for embalming chemical function?

use a buffer, which helps overcome pH differences by keeping pH at a stable range

buffers

• resist change to pH

• a chemical composed of a weak acid and its conjugate base to resist change

• common embalming buffers are:

  • borates

  • EDTA (ethylenediaminetetraacetic acid)

salts

ionic substances that contain metallic and nonmetallic elements

normal salt

all of the replaceable hydrogen of the corresponding has been replaced by metal

acid salt

only part of the replaceable hydrogen of the acid has been replaced by a metal

basic salts

contain a metal and one or more replaceable hydroxide ions

ionization

the dissociating of a substance into ions (charged species)

• can be thought of as dissolving a salt in water

  • presence of ions in a solution enable the transfer of electricity

what is electrolysis

the passage of an electrical current through a solution

most embalming fluid is made of what chemicals

organic chemicals

where did chemicals used in the modern funeral home originate from?

remains of aquatic plant and animal life that were exposed to the effects of temp/pressure/time. the result is commonly called oil/natural gas/coal

75% of a barrel of crude oil is for fuel, the other 25% is used for making other stuff like embalming fluid ingredients

what is oil a mixture of?

• paraffins and isoprenoids (fuel)

• aromatics

• asphaltenes

• nitrogen, sulfur, and oxygen (NSO) containing compounds

all of these compounds are isolated from crude oil by fractional distillation

steps of distilling oil

1. oil is distilled into many fractions, low boilers are removed first followed by subsequent higher boiling fractions

2. individual fractions can be processed more into useful starting materials for the chemical industry

3. NSO compounds, paraffins, and isoprenoids are useful for starting materials for embalming fluid ingredients

nature of organic chemicals

• almost exclusively covalent in nature

• compared to ionic (inorganic) compounds they have:

  • lower boiling and melting points

  • not necessarily water soluble

nature of embalming fluid

EF is a mix of organic chemicals that accomplishes many things at once including:

• preserving

• hydrating (or dehydrating depending on the case)

• perfuming

• colorizing

• water treating

• cell penetration (surfactants)

carbon characteristics

• tetravalent, can form 4 bonds (4 valence electrons)

• carbon-carbon is the most important bond in organic chem

functional groups

the structural features that allow us to classify compounds by reactivity

• one part of a larger molecule

• composed of an atom/group of atoms in a characteristic chemical behavior (a given functional group behaves similiarly)

• characteristic and predictable behavior

• behaves the same way in every compound

example: aldehyde function - formaldehyde and glutarldehyde both have C=O bonds and therefore have similar chemistries

alcohol purpose and chemical example in funeral service

solvent/preservative, ethanol

ether purpose and chemical example in funeral service

N/A, none

arene purpose and chemical example in funeral service

morphine backbone / fragrance, phenanthracene

phenol purpose and chemical example in funeral service

disinfectant/cauterant/bleaching agent, m-cresol

aldehyde purpose and chemical example in funeral service

preservative/disinfectant, formaldehyde

ketone purpose and chemical example in funeral service

cleaning solvent, acetone

carboxylic acids purpose and chemical example in funeral service

anticoagulant/water conditioner, oxalic acid

ester purpose and chemical example in funeral service

fragrance, ethyl acetate

amide purpose and chemical example in funeral service

protein type linkage, methyl formamide

amine purpose and chemical example in funeral service

product of decomp, putrescine

drawing chemical structures

• carbon atoms drawn for emphasis, otherwise they are presumed to be present at intersections

• hydrogen atoms bonded to carbon are typically omitted to avoid clutter

• all atoms other than carbon are shown (heteroatoms)

alkanes

series of compounds that contain carbon and hydrogen atoms with single covalent bonds

• carbon chains linked by single bonds

• most recognized as a fuel source for engines - octane

• also common in waxes/lubricants/asphalt

isomers

same molecular formula, different connectivity

naming compounds

1. find longest continuous carbon chain and use as parent name of compound

2. number the carbons so that branch points have the lowest # possible

3. locate and name all alkyl groups attached to the longest

cycloalkanes

alkanes in a ring form, similar chemistry to their open-ring cousins

alkenes

• hydrocarbons that contain a carbon-carbon double bond functional group

• double bonds are abundant in nature and important biologically and as industrial chemicals

• also called unsaturated

alkynes

• another type of unsaturated hydrocarbon

• has triple bonds

• prevalent in natural products

• alkynes make the world go round

terbinafine

antifungal medicine that contains both a double bond and a triple bond, used to treat athletes foot and jock itch