Atoms, Moles & Stoichiometry.

thoughts: 2 march, 9'44pm.
Just realised something bad, i have near-zero science foundation. Sighs, i have to buck up more and revised O'level"s syllabus already. There'll be test tomorrow too and i think i might flang it though, =x. oh wells enough chitty-chatty, i'll do as much as i can to study a bit for the test.


Atoms, Moles & Stoichiometry: 9'57pm.
(i'm quite surprised that the notes were easy enough for me to understand every word, thanks for the notes ms jee!)

Basically this set of notes start by re-introducing the SI(Systeme International) system, the 7 basic SI Units and a few non-SI units used in chemistry stated below:

Name:..........................Symbol:........Quantity:
Minute.........................min.............time
Atomic mass unit.......u..................mass
Bar...............................bar..............pressure
Atmosphere................atm.............pressure

Then it goes onto the Derived units used in chemistry..
Pascal, Joule, Coulumb, Volt, degree celsius, etc.
As it continues it also covers on how to answer some calculations with respect to certain significant number.


Then it comes to the key conclusion on how to calculate the products formed after the process. Like stated in the example; CaCO3(s) ----> CaO(s) + CO2(g)

Mr of CaCO3(s) = 40.1 +12.0 + (16.0 x 3)
..........................= 100.1

Mr of CaO = 40.1 + 16.0
...................= 56.1

No. of mole of CaCO3 = 25.0/100.1
.....................................= 0.2497 mol

Since 1 mol CaCO3 produces 1 mol CaO,
.: No. of mole of CaO = 0.2497 mol.

Mass of CaO = 0.2479 x 56.
.......................= 14.01 g
.......................~ 14.0 g (3 s.f)


*yeah, that sums up all the info in the notes. Time to sleep! I left some definitions below for referance, feel free to keep readind. =) chal people!



DEFINITIONS:
atom: the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction; the number of protons determines the identity of the element.

moles: The amount of a substance that contains as many atoms, molecules, ions, or other elementary units as the number of atoms in 0.012 kilogram of carbon 12. The number is 6.0225 × 10²³, or Avogadro's number. Also called gram molecule.

stoichiometry: The art or process of calculating the atomic proportions, combining weights, and other numerical relations of chemical elements and their compounds.