INS 6

Water

The most common VEHICLE used in embalming solution

Percentage of Water of the Earth’s Surface

71%, Water Constantly Changing Physical State

Percentage of Water in Adults

65%

Percentage of Water in Children

78%

Physical Properties of Water

High Boiling Point relative to low molecular mass

Higher Melting Point, Heat of Fusion, and Heat of Vaporization are relative to size

Water Density

The solid is less dense than the liquid

Water is Polar

Has a negative region (localized around the oxygen) and a positive region (localized around the hydrogen molecules)

Dipole

Two polarities

Allows for a chemical interaction between 2 water molecules (hydrogen bonds)

Hydrogen bonds are

~5% as strong as covalent bonds

Hydrogen Bonding is an important factor in:

Important factor in the “odd” boiling temperature of water.

Hydrogen bonding pattern can also happen

Between Nitrogen and Hydrogen

Electronegativity is a key factor in the strength of:

Hydrogen bonding

Which of the following is more electronegative?

O

Water AMU

AMU = ? (H-1amu,O-16amu)
(H=1 proton)

(O=8 protons and 8 neutrons)

Water Bond Angle

~105°
• High boiling point (relative to molecular mass) Hydrogen bonds must be disassociated

Hydrogen bonding creates:

A lattice of molecules.

Water is known as the

“Universal solvent”

• Gasses – Formaldehyde

• Liquids – Glutaraldehyde

Hydrogen Bonds Give to Water:

1. Give a high specific heat. (This makes water a good coolant)

2. Give water a high surface tension

Water can be described as “sticky” because

Hydrogen bonds give water a high surface tension.

• Can be observed as the meniscus in a test tube or straw or as a water drop on your car’s surface.

Surface Tension in Embalming

Limits distribution of arterial solution through the capillary beds.

• Embalmers use “surfactants” to overcome this molecular cohesion.

Hydrates

Inorganic salts with water molecules combined into their structure at a definite ratio. Salts in this form are said to be hydrated

• Tend to look like crystals

Hygroscopic compounds

Hydrates that can easily take up water

• Packing desiccants for shipping

Deliquenscence

The phenomena when a hydrate absorbs enough water from the air that it liquifies

Anhydrous

A SUBSTANCE without water.

In embalming, anhydrous chemical such as Plaster of Paris or Gypsum are used as:

Desiccants to absorb body fluids and rebuild features

Anhydride

A HYDRATE that has no water

Hydrolysis

1. Water is split

2. Breaks apart (decomposes) other nearby molecules

3. Atoms from the water molecule and other compound form new compounds.

Hydrolysis in Enbalming

A major factor in the decomposition of human remains.
• A large part of the human body is water

How does Hydrolysis affect a body if it is in humid versus an arid environment?

Hydrolysis speeds up and breaks down body tissues faster in a humid environment as there is more moisture in the air.

Which would decompose at a faster rate? A body in a pool or a body next to the pool on dry land?

A body in a pool decomposes faster

Aldehydes in Embalming

“Crosslink” proteins via an methylene bridge
• Renders the proteins stable against hydrolysis.
• Dehydrates tissue, removing water also minimizes hydrolysis in human remains.

Water in embalming:

The primary vehicle in embalming fluid and embalming solutions
• In embalming: An embalmer mixes a bottle of embalming fluid with water to create an embalming solution

Vehicle

A liquid that serves as a solvent for many ingredients.

Hard Water is caused by:

The presence of sulfate and chloride salts of calcium and magnesium
• These chemicals are present in tap water
• Tap water is the standard vehicle for embalming solution

Temporary Hardness (Not practical)

Bicarbonate salts of calcium and magnesium
• Can be removed by boiling followed by filtration
• Not practical for embalmers

Permanent Hardness

Commonly the sulfate and chloride salts of magnesium and calcium.
• Cannot be removed by boiling.

Calcium

Important in the blood clot formation.

Calcium in Embalming:

Calcium in the water could create clots, thereby decreasing distribution of arterial solution.
• Salt build up could also potentially collect in a cavity injector air displacement system. Make sure to clean instruments properly

Anticoagulants (supplemental fluid)

Is used to bind calcium and minimize clots during the embalming process.
• These chemical will help keep the blood in a liquid state and promote drainage

Water Correctives

Treat the water that is in the embalming tank.

Homogenous mixtures

True solutions

Aqueous Solutions

Solutions made with water

• Blood, milk, embalming fluid

Gas Solutions

Air – a mixture of O2, Nitrogen and other molecules

Solid Mixtures

Alloys – Bronze (copper and tin) used in the manufacture of caskets and urns

Solvent

Does the dissolving

Solute

item being dissolved

Solution =

Solute + Solvent (vehicle)

Embalming Solution =

Water + Embalming fluid

Solubility

How much solute that will dissolve in a solvent

• There is a maximum solubility

  • Imagine too much sugar in iced tea.

Insoluable

Not every compound is soluble in water.

Miscible

Like dissolves like; Polar substances will dissolve polar substance

Nonpolar substances will dissolve nonpolar substances

Immiscible

Polar will not dissolve nonpolar (oil and water)

Natural World Solubility Influences

• Agitation (Mixing)

• Surface Area (size of molecule)

• Temperature

  • Increased temp accelerates chem. reactions (sometimes)
    • Decreased temperature slows chemical reactions (sometimes)

Embalming World Solubility Influences

• Agitation
  • Most embalming machines have a mix function that agitates the embalming solution.

• Surface Area: The molecules used in embalming are small, relative to volume of water used

• Temperature: Typically tepid (lukewarm) tap water is used to
  create an embalming solution

Endothermic

1. Ambient temperature goes
   down

2. Heat is absorbed by the reaction

3. solute + solvent heat → solution

Exothermic

1. Ambient temperature goes up

2. Heat is released from the reaction

3. solute + solvent → solution + heat

Qualitative Concentration is

Important for creating solutions

Concentration:

1. The amount of a solute in a solvent

2. The amount of a preservative in a vehicle

Concentrated solution

Relatively large amounts of solute

Dilute

Relatively low amounts of solute

Unsaturated

A solution that has not yet reached saturation

Saturated

A solution that contains the maximal amount of solute

Supersaturated

A solution that contains more than the maximum amount of solute

Quantitative Concentration Terms

Use of precise terms that provide details about the concentration

Weight percentage of solution

1. Weight by mass (g/g)= Mass of solute/ mass of solution

2. Weight by volume (g/mL) mass of solute/ mass of solution

Ratio

Mass of solute:Mass of solution

Parts Per Million (ppm)

Used for very dilute solution - CH₂O monitoring

Index

The amount of pure formaldehyde gas, by weight in grams, in 100ml of solution

• Refers ONLY to formaldehyde

Properties of Solutions

Different than the corresponding solvent

• i.e. melting points, boiling points, etc.

Diffusion of the solute into the solvent

The movement of solute from an area of greater concentration to one of lesser concentration

Diffusion can be modified by:

Agitation, Amounts, or Temperature

Osmosis

The movement of a solvent through a semipermeable membrane from an area of lesser concentration to one of greater concentration

Isotonic

Two solutions have equal concentrations

Hypertonic

Solution A is more concentrated than Solution B

Hypotonic

Solution A is less concentrated than Solution B

Crystalloid Solutions

True solutions, Homogenous
Does NOT filter or pass through a membrane or precipitate on standing

Not visible

Colloids (shampoo, milk and blood)

Does NOT precipitate on standing
NOT filtered but CAN pass through a membrane

Visible with electron microscope

Suspensions (Soft Scrub Bleach TM)

Can be filtered, Particles settle and separate
Do NOT pass through membranes

Visible to the eye

Qualitative Concentration Terms

Important for creating solutions

Concentration, Concentrated Solution, Dilute