Stoichiometry
3.1 Atomic Masses
All the masses in the modern periodic table are relative to Carbon, where C
is given a mass exactly of 12 atomic mass units (amu).
Mass spectrometer is used to compare the masses of atoms, it is an
instrument which delocalizes electrons from a sample atom using a beam of
high speed electrons, which is later accelerated through a magnetic field;
the deviation from the path formed by original C-12 is measured as a ratio,
which is later multiplied by C-12 mass to give the relative mass of the atom.
Atomic mass is an average value based on isotopic composition of an
element.
A mass spectrometer is also used to determine the isotope composition of
a natural element.
3.2 The Mole
A mole is the number equal to the number of Carbon atoms in exactly 12g
of Pure C-12.
Avogadro’s number, known as the mol, is 6.022x1023
A mole can also be considered as the ratio between the mass of an atom in
grams to its molar mass.
3.3 Molar Masses
Molar mass is the mass in grams of 1 mole of a compound.
For ionic compound, the term formula weight is utilized, as there is no
actual covalent relation between multiple elements in an ionic substance.
3.4 Conceptual Problem Solving
First, we should read the problem and decide where we are going, what are
we seeking for.
Next, we must sort out the key facts given in the information of the
problem.
Develop a procedure either back-to-forth or from reactants to products to
approach the problem. Recall any formulas or relations we must express in
order to solve the problem.
Verify the solution that we have reached to.
3.1 Atomic Masses
All the masses in the modern periodic table are relative to Carbon, where C
is given a mass exactly of 12 atomic mass units (amu).
Mass spectrometer is used to compare the masses of atoms, it is an
instrument which delocalizes electrons from a sample atom using a beam of
high speed electrons, which is later accelerated through a magnetic field;
the deviation from the path formed by original C-12 is measured as a ratio,
which is later multiplied by C-12 mass to give the relative mass of the atom.
Atomic mass is an average value based on isotopic composition of an
element.
A mass spectrometer is also used to determine the isotope composition of
a natural element.
3.2 The Mole
A mole is the number equal to the number of Carbon atoms in exactly 12g
of Pure C-12.
Avogadro’s number, known as the mol, is 6.022x1023
A mole can also be considered as the ratio between the mass of an atom in
grams to its molar mass.
3.3 Molar Masses
Molar mass is the mass in grams of 1 mole of a compound.
For ionic compound, the term formula weight is utilized, as there is no
actual covalent relation between multiple elements in an ionic substance.
3.4 Conceptual Problem Solving
First, we should read the problem and decide where we are going, what are
we seeking for.
Next, we must sort out the key facts given in the information of the
problem.
Develop a procedure either back-to-forth or from reactants to products to
approach the problem. Recall any formulas or relations we must express in
order to solve the problem.
Verify the solution that we have reached to.
