·
Atoms:
Smallest particle of any element
which may or may not exist independently.
·
Molecule:
At least two or more atoms chemically
combined together. It can exist independently.
·
Nucleon Number/Mass Number:
The total number of protons and
neutrons in the nucleus of an atom.
· Atomic Number:
The number of protons in an atom.
·
Molecular Formula:
The actual number of atoms each
element present in one molecule of a compound.
·
Empirical Formula:
The formula that tells us the simplest ratio of the different atoms present in the molecule.
Example:
Molecular
Formula Empirical
Formula
c₆H₆ = n X CH
n = molecular
formula mass/ empirical formula mass
(n = whole
number/ positive integer)
·
Isotopes:
Atoms with the same number of protons
but different number of neutrons.
·
Relative Atomic Mass:
The average weight mass of an atom
compared to1/12 the mass of a C-12 atom.
·
Relative Isotopic Mass:
Mass of an isotope compared to1/12
the mass of a C-12 atom.
·
Relative Molecular Mass:
The average mass of the molecules compared
to1/12 the mass of a C-12 atom.
·
Relative Formula Mass:
The mass of one formula unit of a
compound compared to1/12 the mass of a C-12 atom.
(Same as relative molecular
mass)(Used for compounds containing ions)
·
Moles:
Amount of substance that contains
Avogadro’s number of particles (6.02 x 10²³)
(It is the Ar/Mr expressed in grams)
1) No. of moles =
mass (grams)/Mr (Molar Mass)
2) No. of moles =
Volume(dm³) X Concentration(mol/dm³)
·
Avogadro’s Gas Law:
Under similar condition of
temperature and pressure, the molar ratio corresponds to the volume ratio and
vice versa.
·
Hydrocarbons:
Compounds containing carbon and
hydrogen only
CxHy + (x+y/4) O₂ → xCO₂ + (y/2) H₂O (general equation)
·
Combustion:
Burning in the presence of O₂
·
Combustion Analysis Tube:
Hydrocarbon enters the furnace .it is
first passed through a Carbon dioxide absorber (NaOH) and then through a
Moisture Absorber (MgClO₄)
Sample Question:
Data:
Before Process
|
After Process
|
100g MgClO₄
|
150g MgClO₄
|
100g NaOH
|
150g NaOH
|
Now you can calculate the following
by substituting the values below:
% Mass of Carbon = 2/44 x mass of CO₂ x 100%
% Mass of Hydrogen = 2/18 x mass of
HO₂ x 100%
% Mass of Oxygen = 100 – (% of carbon
+ % of hydrogen)
Mass of Oxygen = Weight of
sample-(Weight of carbon + weight of hydrogen)
·
Mass Spectrometer:
Mass spectrometer provides the
following information:
1) Number of isotopes of atom
2) Relative abundance of each isotope
3) The relative atomic weight of an atom
Sample: Mass spectrum of neon, Ne.
Ar of neon = (20 x 90.9) + (21 x 0.3)
+ (22 x 8.8) / 100 = 20.2
Here is a link to my drive, you can download the original file here:
This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.
ConversionConversion EmoticonEmoticon