Chemical Hazards Flashcards
Density
Mass Per Unit= Mass object/ Volume of Object
Specific Gravity: Definition
Specific Gravity of a liquid or solid is defined as the ratio of the mass of the liquid or solid to the mass of an equal volume of water. The ratio of density of a gas or vapor to density to density of air is called vapor density.
Specific Gravity: Equation
Mass of solid or liquid/ Mass of an equal volume of water at 4 degrees.
Temperature Conversion: Fahrenheit to Celsius
F-32 / 1.8 = C
Rankine Temperature Conversion
F + 460= R
Kelvin Temperature Conversion
C + 273 = K
Atom defintion:
The number of electrons and protons in any atom are equal, so that the atom, in its normal state, is neutral. The number of protons in any atom is called the atomic number, and the number of protons and neutrons the atomic mass.
Isotope Defintion:
Isotopes are atoms of a given matter with the same atomic number, but different atomic mass, i.e, the number in all atoms are equal but the number of neutrons are different.
Molecular Weight
The sum of the atomic weight of different atoms making a compound is called the molecular weight of that compound.
Mole
The average chemical experiment involves the reaction of an enormous number of molecules. In order to simplify calculations, one mole of a substance is defined as the mass of that substance which contains exactly 6.023 x 10*23 molecules. (Avogadro’s Number) In order to convert the mass of a given substance to moles, we divide the mass by the molecular weight of that substance.
Mole Conversion:
Mass/Molecular Weight
Gram Mole Conversion:
Mass expressed in grams/ Molecular weight
Valence:
The electrons in the outer orbit of an atom are called the Valence electrons, which are responsible for chemical reactions.
Ionic Bonds:
When one or more valence electrons are transferred from one atom to another, the atom that has lost the electrons becomes positively charged (positive ion). A strong electrical force will be developed between the positive and negative ions which form a new compound.
Covalent Bonds
Some chemical reactions take place when atoms “share” their valance electrons to complete the electron requirement in the valance shell of each atom. Much weaker than ionic bonds.
Atomic Absorption
Atomic absorption is an analytical technique which takes advantage of the characteristic absorption by metals of certain wavelength of light.
Electronegativity
Electronegativity is a property associated with certain atoms which causes unequal sharing of electrons during bonding. This results in shared electrons spending more time one atom and less time with the other.
Heat of Reaction
There is a certain amount of energy associated with each chemical bond. In a chemical reaction the sum of the energy of the chemical bonds in the products is usually different from the bond energies in the reactants.
Isomers
Substance that have the same number of atoms of each element per molecule but differ in spatial arrangement of the atoms are known as isomers of each other.
Crystals
A crystalline substance is an ORDERED array of its component atoms, ions, or molecules.
Oxidation-Reduction Reactions
Oxidation refers to the loss of electrons by atom involved in a chemical reaction. Reduction is the gain of electrons by an atom involved in a chemical reaction. Oxidation is always accompanied by reduction. These reaction are more common known as Redox reactions.
Avogadro’s Number
The number of atoms of an element in one gram of that element.
6.024 x 10*23
Vapor Pressure
Vapor Pressure of a liquid is defined as the pressure exerted by the vapor when the liquid and vapor phases have reached equilibrium. Alway increase with heat.
Heat:
Heat is energy in transfer
Specific Heat:
The amount of heat expressed in calories which s required to raise the temperature of 1 gram of substance by one degree Celsius or the amount of heat expressed in BTU(British Thermal Units) which is required to raise the temperature of one pound of substance by one Fahrenheit.
Heat of Fusion
The amount of heat required to melt 1 unit mass of the solid at its melting point without changing its temperature.
Heat of Vaporization
The amount of heat required to vaporize 1 unit mass of liquid at its boiling point without changing its temperature.
Heat of Sublimation Definition:
The amount of heat required to convert 1 unit mass of a solid to vapor without changing its temperature.
Heat of Sublimation Equation:
Heat of Fusion + Heat of Vaporization
Compressible Fluid
The volume changes significantly with changes in pressure or temperature. For example, by pressurizing a gas, we can reduce its volume substantially. Therefore, gases are considered to be compressible.
Incompressible Fluid
The volume does not change significantly with changes in pressure or temperature. For example, if we increase the pressure on a liquid, its volume does not change substantially. Therefore, liquids are consider to be incompressible.
Mole
Mass divided by the molecular weight.
Mixture Equation
a = M/V
Ideal Gas Law
PV = nRT
Absolute Pressure and Temperature Scales Equation:
Absolute pressure = Gauge pressure + Atmospheric pressure
Degrees Kelvin = C + 273
Degrees Rankine = F + 460
Standard Conditions
Reference temperature of 0 degrees and pressure 1 ATM are commonly referred to as standard temperature and pressure(STP)
Combined Gas Law
When the state of an ideal gas is changed from condition 1 to 2, the relation between pressure, temperature, and volume is given by: P1V1T2 = P2V2T1 or P1V2/T1 = P2V2/T1
