Nov,22--Harder Mole Conversions

Mole Map





Nov.17--The Mole

Equal volumes of different gases at the same temperature and pressure have the same number of particles.

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Avogadro’s Hypothesis: If they have the same number of particles, the mass ratio is due to the mass of the particles.

Atomic Mass: mass of one atom of the element in atomic mass units

Ex. Fluorine = 19.0 amu

Formula Mass: mass of all the atoms of a formula of an ionic compound (in amu)

Ex. Potassium Fluorine = K (39.1) + F (19.0) = 58.1 amu

Molecular Mass: mass of all the atoms of a formula of a covalent compound (in amu)

Ex. Carbon Dioxide = C (12.0) + O₂ (16.0×2) = 44.0 amu

   express in grams per mole: 44.0 g/mol

1 mole of oxygen = 16.0 g/mol

1 mole of carbon = 12.0 g/mol

• They have the same number of particles!
 

 

Youtube Video: introduction to the idea of a mole as a number
http://www.youtube.com/watch?v=AsqEkF7hcII 

Avogadro’s Number: The number of particles in 1 mole of any amount of substance is:

  particles/mol

Nov.5--(Lab 2E) Determining Aluminum Foil Thickness

In order to find out the thickness of aluminum foil, you must remember the formula:

 D= M/ V

(D: density, M: mass, V: volume )



Equipment:
3 rectangular pieces of aluminum foil

metric ruler

centigram balance

Procedure:
1.Use a metric ruler to measure the length and width of each piece of foil.
2.Use a centigram balance to find the mass of each piece of foil
(Using significant figures to record the quantities)
3.Density of aluminum foil is 2.70g/cm’3
4.Calculate the volume use: V= M/D
5.Then H=V/LW (should be expressed in scientific notation)



Experimental Error:
(your measurement - Accepted value) / Accepted value*100  %

Nov,1--Density

Density = Mass/Volume *(D=M/V)

- unit for liquid is g/mL

  unit for solid is g/cm3

How to calculate density ? There is a Youtube Video can help you understand better.

*The density of water is 1g/mL

-If the density of an object is greater than the density of the liquid---- sink

 If the density of an object is smaller than the density of the liquid---- float

A Youtube Video about sinking and floating in liquid