(Q2) Oxygen & Hydrogen, Water (pg. 1-7) Flashcards
Facts about Oxygen
- Nonmetal
- Most abundant element on Earth
- 21% of the volume of atmospheric air
- 89% of the mass of water
- Formula: O2 Symbol: O
Oxygen on the Periodic Table
- VIA Element
- 6 valence electrons
- Oxygen means “acid former”
- When combined with some inorganic elements, acids form
Oxygen’s Physical Properties
- Colorless, odorless. & tasteless
- Heavier than air
- Slightly soluble in water
- Can be liquified & solidified by extreme pressure & low temperature
Oxygen’s Chemical Properties
- Reacts with many substances slowly at ordinary temperatures but rapidly at high temperatures
- Reacts with many metallic & nonmetallic elements to form oxides
- Supports combustion/helps things burn
Ways to define Oxidation
- the addition of oxygen to a substance
- the removal of hydrogen from a substance
- the removal of electrons from a substance
- the increase in oxidation number of a substance
Forms of Oxygen
O: Nascent oxygen
O2: Molecular oxygen (atmospheric oxygen)
O3: Ozone
Allotropic
When an element exists in two or more different forms, each with its own physical & chemical properties
O,O2,O3
Facts about Hydrogen
- Most abundant element in the universe
- found in both organic and inorganic compounds
- Tissue gas is largely free hydrogen
- Atmospheric Hydrogen: H2 (diatomic molecule)
- Atomic Number 1
- 1 Valence Electron
Physical Properties of Hydrogen
Colorless, odorless, tasteless gas
Lighter than air
Slightly soluble in water
Chemical Properties of Hydrogen
- Burns with hot, blue flame forming water
- Doesn’t support combustion
- means “water producer”
Ways to Define Reduction
The removal of oxygen from a substance
The addition of hydrogen to a substance
The addition of electrons to a substance
The decrease in oxidation number of a substance
Facts about water
- most abundant compound on earth
- Covering about 75% of the earths surface
- Present in air as water vapor
- Found in all plant and animal tissue
- Human body consist of about 50 to 60% water
- bacterial cells contain about 85% water
Water on the periodic table (facts about water)
- H2O
- Bent molecule; 105°
- atomic mass of 18
Physical properties of water
- Colorless odorless tasteless liquid
- Freezes at 0°C
- boils at 100°C
- Very good solvent for many substances
- heat of a vaporization: 450 cal per gram
Hydrogen bonding
Attractive force that exists among molecules
Water molecules are polar, which means there is a positive and negative pole
The positive side is attracted to the negative end of another pole
Properties of electronegativity apply
Surface tension
A force that causes the surface of a liquid to contract
Caused by hydrogen bonding
Water has high surface tension
Why is surface tension important to embalmers?
Surface tension is important because it occurs between arterial solutions and cell membranes
- Interferes with the diffusion of embalming chemicals from the capillaries into the tissues
- To overcome this problem, use surface tension reducing agents in embalming fluids
Chemical properties of water
- Very stable substance
- Thermally stable
Chemically reacts with active metals to liberate hydrogen - Reacts with metallic oxides to form bases
- Reacts with non-metallic oxide to form acids
- Forms hydrates
- Enters into hydrolysis reactions
- Key factor in decomposition
