Chemical Hazards

Question 1

Density

Answer 1

Mass Per Unit= Mass object/ Volume of Object

Question 2

Specific Gravity: Definition

Answer 2

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.

Question 3

Specific Gravity: Equation

Answer 3

Mass of solid or liquid/ Mass of an equal volume of water at 4 degrees.

Question 4

Temperature Conversion: Fahrenheit to Celsius

Answer 4

F-32 / 1.8 = C

Question 5

Rankine Temperature Conversion

Answer 5

F + 460= R

Question 6

Kelvin Temperature Conversion

Answer 6

C + 273 = K

Question 7

Atom defintion:

Answer 7

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.

Question 8

Isotope Defintion:

Answer 8

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.

Question 9

Molecular Weight

Answer 9

The sum of the atomic weight of different atoms making a compound is called the molecular weight of that compound.

Question 10

Mole

Answer 10

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.

Question 11

Mole Conversion:

Answer 11

Mass/Molecular Weight

Question 12

Gram Mole Conversion:

Answer 12

Mass expressed in grams/ Molecular weight

Question 13

Valence:

Answer 13

The electrons in the outer orbit of an atom are called the Valence electrons, which are responsible for chemical reactions.

Question 14

Ionic Bonds:

Answer 14

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.

Question 15

Covalent Bonds

Answer 15

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.

Question 16

Atomic Absorption

Answer 16

Atomic absorption is an analytical technique which takes advantage of the characteristic absorption by metals of certain wavelength of light.

Question 17

Electronegativity

Answer 17

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.

Question 18

Heat of Reaction

Answer 18

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.

Question 19

Isomers

Answer 19

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.

Question 20

Crystals

Answer 20

A crystalline substance is an ORDERED array of its component atoms, ions, or molecules.

Question 21

Oxidation-Reduction Reactions

Answer 21

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.

Question 22

Avogadro’s Number

Answer 22

The number of atoms of an element in one gram of that element.
6.024 x 10*23

Question 23

Vapor Pressure

Answer 23

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.

Question 24

Heat:

Answer 24

Heat is energy in transfer

Question 25

Specific Heat:

Answer 25

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.

Question 26

Heat of Fusion

Answer 26

The amount of heat required to melt 1 unit mass of the solid at its melting point without changing its temperature.

Question 27

Heat of Vaporization

Answer 27

The amount of heat required to vaporize 1 unit mass of liquid at its boiling point without changing its temperature.

Question 28

Heat of Sublimation Definition:

Answer 28

The amount of heat required to convert 1 unit mass of a solid to vapor without changing its temperature.

Question 29

Heat of Sublimation Equation:

Answer 29

Heat of Fusion + Heat of Vaporization

Question 30

Compressible Fluid

Answer 30

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.

Question 31

Incompressible Fluid

Answer 31

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.

Question 32

Mole

Answer 32

Mass divided by the molecular weight.

Question 33

Mixture Equation

Answer 33

a = M/V

Question 34

Ideal Gas Law

Answer 34

PV = nRT

Question 35

Absolute Pressure and Temperature Scales Equation:

Answer 35

Absolute pressure = Gauge pressure + Atmospheric pressure
Degrees Kelvin = C + 273
Degrees Rankine = F + 460

Question 36

Standard Conditions

Answer 36

Reference temperature of 0 degrees and pressure 1 ATM are commonly referred to as standard temperature and pressure(STP)

Question 37

Combined Gas Law

Answer 37

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