Converting between Moles to Molecules to Atoms

In this conversion, A mole of any substance is 6.02×10²³ molecules of that substance.

To convert moles to atoms, you first convert the mole to molecules then use the element's subscripts and multiply it to the answer.

0.001 moles water ×

(

6.02×1023 water molecules 1 mole water

)

= 6.02×1020 water molecules

100 water molecules ×

(

1 mole water 6.02×1023 water molecules

)

= 1.66× 10-22 moles water

http://www.youtube.com/watch?v=21tLXgeYALc

Molar Mass

• The mass (in grams) of 1 mole of a substance is called the molar mass
• it can be determined from the atomic mass on the periodic table
• measure in grams over moles (g/mole)

Molar Mass of Compounds

• to determine the molar mass of a compound add the mass of all the atoms together

Element:

FeO- 55.8=16.0=71.8 g/mol

NO- 14=2(16)= 46.0 g/mol

PCl˅5- 31.0+5(35.5)= 208.5 g/mol

Na˅2SO˅4- 2(23.0)=32.1+4(16.0)= 142.1 g/mol 

H˅2O- 2(1.0)=16.0= 18.0 g/mol 

AlCl˅3- 27.0=3(35.5)= 133.5 g/mol

http://www.youtube.com/watch?v=ZqS38Il8--s

By: Krysta Del Rosario :D

Moles to Volume Conversion

At a specific pressure and temperature, one mole of any gas always have the same volume.
1) At 0 degree C and  101.3 kPa: 1 mol= 22.4 L
- This temperature and pressure is called STp
   - 22.4 L/mol is the molar volume at STP

Example:

How many litres will 4.7 mol of O2 have at STP?

4.5 mol x  22.4 L  = 1.0 x 10^2 litres
                  1 mol




http://www.youtube.com/watch?v=AHqNiEwcXiE

- Candace Chan

Mole Conversions (Converting between grams and moles)

Converting between moles and mass(grams):
1) To convert the units, we use molar mass as the conversion factor. Molar mass is the number of atomic mass added together.
2) Be sure to cancel out the appropriate units.
* remember about the significant digits!
Examples:

How many grams are in 2.5 mol of Cl2?

2.5 mol x   71g      = 1.8 x 10^2 grams
                1 mol
           
How many moles are there in 205g of BeF2?

205g x   1 mol  = 4.36 mol
                47 g



http://www.youtube.com/watch?v=ehepBBtSbDc

-Candace Chan

Avogadro's Number- 6.02 x 10^23

• Atoms and molecules are extremely small
• Macroscopic objects contain too many to count or weight individually
• Amedeo Avogadro proposed that the only number of atoms in 12.00000g of Carbon be equal to a constant (= 1 mol of C)
• This value is now called Avogadro's number and forms the basis of all quantitative chemistry
• 1.0 mol= 6.02 x 10^22 atom
• 1 pair= 2
• 1 dozen= 12
• 1 century= 100
• 1 mol= 6.02 x 10^23
• One mole represents a huge number of particles

Particle

Atom- element- 6.02 x 10^23/1 mol

Molecule- covalent compound- 6.02 x 10^23/ 1 mol

Formula unit- ionic compound- 6.02 x 10^23/1 mol

Example: 2.47 x 10^25 atoms x 1 mol/ 6.02 x 10^23 atoms = 41 mol

http://www.youtube.com/watch?v=AsqEkF7hcII

By: Krysta Del Rosario :)

Hydrate Lab

  The purpose of this experiment is to determine the empirical formula of a hydrate.
               - Hydrates are ionic compounds that contain an inorganic salt compound loosely bound to water.

In this lab, we try to determine the anhydrous (without water) mass of the hydrate.

We had to determine the mass of water by boiling the substance over the bunsen burner and measure the test tube with the substance to find out how much water was in that substance.

We determuine the percent by using the formula:

% Error= measured - accepted    x 100
                       accepted

- Candace and Reo

Molecular Compounds

·         7 molecules are diatomic

·         2 of the same elements

·         H2, N2, O2, F2, Cl2, Br2, I2

·         2 molecules are polyatomic

·         S8, P4

Naming Molecular Compounds

·         Use the name of the first element

·         Second element ends in-ide

Examples:

N2 O4                         dinitrogen tetraoxide

Cs2                             Carbon disulphide

P4 O10                        tetraphosphorus decaoxide

Nitrogen trichloride          Ncl3

Sulfur dibromide                SBl2

Naming Acids and Bases

·         Hydrogen compounds are acids.

·         HCl(aq) ------------> hydrochloric acid

·         H2SO4(aq) --------------> Sulfuric acid

Acids/Bases to memorize

·         Hydrochloric acid -----------> HCl

·         Nitric Acid -------------> HNO3

·         Sulphuric Acid -----------> H2SO

Example

-HOCCCOOH(aq) ------------------------> C2 O4 (-2)

-Reo

Lewi Dot Diagram

Drawing Electron Dot Diagram:    -the nucleus is represented by the atomic symbol
                                                        -determine the number of valence electrons
                                                        -electrons are represented by dots around the symbol
                                                        -max. electrons each orbital can hold goes 2,8,8...
Example:                                                             Lithium

-in covalent compounds electrons are shared

      Determine the number of valence electron for each atom in the molecule.

      Place atoms so that valence electron are shred to fill each orbital.

-in ionic compounds electrons transfer from one element to another
      Determine the number of valence electrons on each ions
      Put brackets around the metal and non-metal
      Write the charge at the top right of the brackets


-Stanley K.

Trends on the periodic table.

Elements close to each other on the peroidic table displaysimilar characteristics.
Theres 7 trends to elements: -Reactivity
                                              -Ion Charge
                                              -Melting Point
                                              -Atomic Radius
                                              -Ionization energy
                                              -Electronegativity
                                              -Density

Reactivity
-Metals and non-metals show different trends
-Most reactive metal is Francium
-Most reactive non-metal is Fluorine

Ion charge
Elements ion charges depend on their group


Melting point
Elements in center -> highest M.P.
Noble gases -> lowest M.P.
L<R til middle

Atomic Radius
Decreases from left bottom to top right
Helium smallest
Francium largest

Ionization Energy
the energy needed to completely remove an electron from an atom
Increases from bottom left to top right
All noble gases have high I.E.
Helium highest
Francium lowest

Electronegativity
How much atoms wants to gain electrons
Same trend as Ionization energy

-Stanley K

Isotopes & Atoms

Atomic Number: Number of Protons


Atomic Mass- Atomic Number= Number of Neutrons

Mass Spectrometers are used to determine the abundance and mass of the isotopes of elements
http://www.youtube.com/watch?v=SeDaOigLBTU


How to calculate the average:

- Change each percent to a decimal by dividing by 100
-Multiply by the mass
-Add it all together

http://www.youtube.com/watch?v=xL86L3qUf34
-Candace Chan

Quantum Mechanics

Quantum Theory was from the Bohr Theory- the theory explains the electron is a particle that must be in orbital in the atom.
            - Orbitals are areas in 3D space where the electrons are.
            - Photons are produced when high energy nodes are change to lower energy nodes.
Quantum Mechanics explains the properties of atoms by treating the electron as a wave and quantizing its energy.

http://www.youtube.com/watch?v=45KGS1Ro-sc

There are 4 types of orbitals: S orbitals, P orbitals, D orbitals and F orbitals.

S Orbitals:
- S orbitals are shaped like a sphere.
- Each orbitals hold 2 electrons.
- Located on the far left side of the periodic table.

P Orbitals:
- P orbitals are shaped like footballs
- Each orbitals contain 2 electrons
       - Have 3 suborbitals
       - Total electrons are 6
- Located on the far right side of the periodic table

D Orbitals:
- D orbitals are shaped like doughnuts
- Each orbitals contain 2 electrons
       - Have 5 suborbitals
       - Total electrons are 10
- Located in the middle of the periodic table

F Orbitals:
- F orbitals are shaped like
- Each orbitals contain 2 electrons
       - Have 7 suborbitals
       -  Total electrons are 14
- Located on the bottom of the periodic table


http://www.youtube.com/watch?v=K-jNgq16jEY
-Candace Chan

Atomic Theory

Democritus:

• Democritus proposed that all mater, the "stuff" that makes up the world around is, is actually composed of tiny, indivisible particles.
• He called them atomos, from which we get the English word atom.
• He would have said that you could not cut a piece of aluminum foil into infinitely smaller pieces. Eventually, you would divide the foil into individual atoms, which he thought could be divided no further.
• An atom is the smallest particle of an element that retains the chemical identity of that element.

Antoine Lavoisier: 

• Lavoisier carefully measured the mass of substances before and after a chemical reaction and found that the masses were always equal.
• no mass was gained or lost in a reaction.
• A chemical reaction neither creates nor destroys matter, but the matter is conserved.

Joseph Louis Proust:

• Proust found that a given compound always contains the same elements in the same proportions by mass.
• For example, the mass of water is always 88.9% oxygen and 11.1% hydrogen.

John Dalton:

• Each element is composed of extremely small particles call atoms.
• All atoms of a given element are identical, but they differ from those of any other element
• Atoms are neither created nor destroyed in any chemical reaction
• A given compound always has the same relative numbers and kinds of atoms

http://www.youtube.com/watch?v=ZnKqiojoFJU

By: Krysta Del Rosario

Bohr Diagrams

NEUTRONS AND PROTONS:

Neutrons and protons are located in the nucleus. Write the number of protons and neutrons inside the nucleus using the symbols ‘p’ and ‘n’.

Number of protons = Atomic Number

Number of neutrons =

Atomic Mass – Atomic Number

ELECTRONS:

Electrons are located in orbitals surrounding the nucleus.

Number of electrons = Number of protons

How many electrons can fit in each orbital?

1^st orbital = 2 electrons

2^nd orbital = 8 electrons

3^rd orbital = 8 electrons

4^th orbital = 18 electrons

Electrons are always in pairs

EXAMPLE:

Chlorine- Cl

Number of Protons (Atomic Number) = 17

Number of Neutrons (Atomic Mass - Atomic Number) (35-17)= 18

Fluorine- F

Number of Protons (Atomic Number)= 19

Number of Neutrons (Atomic Mass - Atomic Number) (19-9)= 10

Aluminum- Al

Number of Protons (Atomic Number)= 13

Number of Neutrons (Atomic Mass - Atomic Number) (27- 13)= 14

http://www.youtube.com/watch?v=iih6rJ2S6pk

By: Krysta Del Rosario :)

Density and Graphing

The Density of an object is it's mass divided by its volume.

d= m/v. and is usually expressed in kg/L, kg/m3, or g/cm3

Ex: d=m/v
       d=135/65
       d= 2.1

Graphing

All graphs must contain 5 important things:
1) Labelled Axis
2)Appropriate Scale
3)Title
4) Data Points
5) Line of Best Fit

To find the slope: m= rise/ run
To find the Area, you must make it into a shape and use the formula of the shape to find the area and add them all up.

-Candace

Dimensional Analysis

There are only 4 steps to converting:
1) Identify what units you want to end up with
2)Find the conversion factors
3) Place units in the appropriate places
4) Cancel units

For example:

? miles = 120 km
120km * 1 mile/1.6 km= 75 mile

 http://www.youtube.com/watch?v=aZ3J60GYo6U

-Candace

Significant digits and Scientific Notation

How we determine what digits are significant:

-all numbers other than 0 are significant

-if the 0 comes after 4 the decimal

·         341----------------> 3

·         41.002 -----------------> 5

·         0.00110 -------------------> 3

-when we add or subtract two numbers we determine the number of significant digits in the answer by rounding the lowest number of significant digits in the initial number.

-When we multiply or divide two numbers we determine the number of significant digits by rounding the lowest significant digits.

-Round only original numbers.

250,000,000 = 2.5x10(8)

0.00940 = 9.4x10(-3)

7,700,000,000,000 = 7.7x10(12)

0.000,000,000,85 = 8.5x10(-10)  

2.57x10(4) = 25700

1.5x10(-5) = 0.000015

8.11x10(7) = 81100000

3.50x10(-3) = 0.00350

What is wrong with writing 25.10(8)?

You cannot have a two-digit number in the front.

2.58x10(8)

-Reo

Metric Units

Metric system

Tera     10(12)                                                  Deci      10(-1)

Giga      10(9)                                                    centi   10(-2)

Mega      10(6)                                                 milli     10(-3)

Kilo          10(3)                                               micro    10(-6)

Hecto      10(2)                                               Nano      10(-9)                                                      

Deca        10(1)                                              Pico         10(-12) 

                                                                        Femto       10(-15)

-gigabyte and megabyte = computers

-error is inescapable because of inaccurate measurements.

Meniscus= a curved surface of a liquid.

Error might occur in an experiment because of:

-inaccurate measurements

-measuring always involves estimation.

Measuring instruments are never completely free of flaws.

Absolute error=    (measurement – accepted)

Absolute percent=     (measurement – accepted %) x100

                                                 Accepted

-Reo

Classification of Matter

-Matters can be classified into Homogeneous substances & Heterogeneous substances
-Homogeneous: consists of only 1 visible component
  -e.g. water, oxygen, graphite, air, brass
-Heterogeneous: contains more than 1 visible component
  -e.g. granite, chocolate chip cookie, sand

                                                                   / Solution
                                      / Homo. Mixtures
            / Homogeneous                                    / Element (e.g. oxygen, Iron)
Matter                                \ Pure Substances
            \ Heterogeneous                                  \ Compound (e.g. water, sugar)
                                       \ Mechanical Mixtures



p.s. Solution   - 2 or more substances
                       - usually involves liquid (e.g. fog, steel)
                       - component in greater amount=solvent
                          - water is the most common solvent
                          - (aq) is used when sth is dissolved in water
                       - component in smaller amount=solute

Seperating Mixtures

-Many methods
    - By hand
    - Filtration      -->   Physical
    - Distillation   -->   Changes
    - Crystallization
    - Chromatography


By Stan K.

Physical vs Chemical Changes

Physical vs Chemical Change

Physical Change
-Involves changing shape or state of matter
-e.g. crushing, tearing etc.
-NO NEW SUBSTANCES ARE FORMED
-e.g. boiling water, cutting wood,smashing cars etc.
http://www.youtube.com/watch?v=w5Y452eiHC8

Phase Changes
 
 Chemical Change
-NEW SUBSTANCES ARE FORMED
-Properties of matter change
-Conductivity, acidity, colour etc.
-e.g. Iron rusting, burning wood.

http://www.youtube.com/watch?v=I8aA7SjYsCA&feature=related

Physical and Chemical Change Video:
http://www.youtube.com/watch?v=5yjEDihEuZI

-Stanley

Balancing and Words Equations

Phase Symbols

• are subscripts that indicate the phase of the chemical
• s: solid
• l: liquid
• g: gas
• aq: dissolved in water/solution

Diatomic Molecules are molecules that contains two atoms : H2, N2, O2, F2, Cl2, Br2, I2

Polyatomic Molecules are molecules that contains more than 2 atoms : P4, S8

H2O: can also be called HOH. H2O can also be called HOH because in some equations, they will use OH. Since to make balancing easier, HOH is use to make OH a whole instead of H and O.

Balancing Equations:




http://www.youtube.com/watch?v=RnGu3xO2h74

-Candace

Lab Safety

Top Ten Lab Safety Rules:

1) Tie back long hair
2) Wear safety equipment
3) No open toed shoes
4) Waft, don't directly smell or sniff
5) Don't fool around
6)Put backpacks under tables
7) Don't mix chemicals unless instructed to
8) Don't use broken equipments
9) Wash your hands after doing a lab
10) Don't play with fire

Safety equipments includes safety goggles, lab coat, no open toed shoes and gloves.

http://www.youtube.com/watch?v=s6lOQ5_Vlok&feature=related

Acetone can break the organic bonds so it can disintegrate like a styroform cup. Acetone is used in nail polish remover and paint thinner.
-Candace

New Partners

Reo Takahashi and Stanley Kwong are added into this group

Hey

Hey, I'm Candace and I'm in Block E Chemistry Class